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(Semi)Automatically Repricing Your Book Inventory
Why and How?

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    White Unicorn Books

Table of Contents
  1. Why Reprice
  2. Repricing – the Basics
  3. Specific Considerations
    1. General Exclusions
    2. Determining Comps
    3. Limitations on Price Changes
    4. GeneralConsiderations
  4. Repricing Programs/Services
  5. Simple Repricing Scripts
    1. Don't reprice on flag
    2. Don't Reprice for greater than Min or less than Max price
    3. Don't raise price if flag is set

Why Reprice       TOP

What I mean by (semi)automatically repricing is having a computer reprice your inventory where you either accept the results without checking the details (the automatic part) or only making a cursory inspection of the results and accepting the great majority of the price suggestions made by the program (the semi-automatically part).

Before we get started though, let me ask you a question: Do you sell only moderately unique items (maybe one to ten available for sale on the major multi-search sites like viaLibri, Bookfinder, Addall, etc.)? If the answer is yes then, IMO, there is no real answer to why reprice. You probably shouldn’t, except rarely, and even then your expertise in pricing is much better than what a computer program can do for you. This article is for the rest of the people who sell (at least in part) new and (moderately) common books. It also means that a part of your inventory should be excluded from repricing unless you only sell new and common books (and even then there may be a few you want to exempt from repricing).

So, why reprice? The obvious answer is “I can sell more books and make more money”. The “and” part of that sentence is important because I know of no-one who wants to sell books just to sell books. They want to make money at it or at least break even. Even those who sell “just for the fun of it” would quickly quit having fun if it cost them several dollars for each book they sold.

However, there is a little more to the “why” than just the simple answer above. Although not necessary for the (less common) used book market, it is becoming much more useful to automatically reprice you inventory in the new book market. Even when you can’'t automatically reprice your books, you can get some help by semi-automatically repricing your books. The number of items in this latter category should not be too large because you would then be devoting to much time to repricing instead of time needed to run the rest of your business. Of course “too large” is relative and some businesses even devote a (part of a) persons time to repricing (think of markdowns, sales, “specials”, remainders, etc.).

One article on repricing is available in the IOBA Standard at The Alibris Pricing Tool and is by Richard Weatherford. The article makes the following observations:” It won't help with your antiquarian or highly specialized books - your expertise will be more accurate than our market data.” and “We know who buys books online - and it is overwhelmingly readers, not collectors. We know which copy they pick - usually the lowest priced one that is not torn, broken, or marked up.”

Another reference is a basic pricing presentation Retail Pricing and Repricing of Merchandise which gives several reasons for repricing. Some reasons given are pricing errors, selling errors, and, of course, the demand for the item. It also discusses other aspects of repricing which we will come to later.

Through the above articles, and many others, we come to the major reason why we should reprice our unsold new and common used books -– supply and demand. Although we have focused mostly on markdowns, let’'s not forget that repricing can also mean markups. When the demand is high and the supply seems inadequate, we might want to price our books over retail. When the demand is high but the supply seems adequate, we can price our books near the same price as Amazon. When the demand starts to become lower and supply starts to exceed demand, we want to lower our price and get rid of what we have. Or put another way, we want to reprice to maximize profit and minimize loss. After all, isn’t it better to make just a small profit or accept just a small loss by selling the books than let the books set around until they are basically unsellable. With the latter, you can get part of your money back by scrapping the books but even in the best case I doubt you could get back more than a few tens of cents on the dollar which is probably less than if you had sold them at a few pennies loss.

Repricing – the Basics       TOP

If we have decided that repricing may work for us, we need to implement the repricing and that is our next subject. Before we continue, we emphasize that the purpose of repricing is to maximize our profit and minimize our losses. We do not want to mark down (or up) any item unless we feel we need to and, in any case, we do not want to become a “penny seller” (nor a "scalper"). In the case of markdowns, we would probably do better with our merchandise by selling the remaining lot on eCrater at a steep discount before we got to the point of penny selling or, in the case of individual items either make lots for eCrater or donate them to the local library, nursing home, childrens center, etc. and get back our few tens of cents on the dollar.

For our purposes we want the markdowns to be sharp enough to move goods, that is make the customer choose our book rather than a competitors or conversely, the markdown should not be so small as to be ineffective.

Repricing scripts should try to mimic the supply & demand market place because that is what is really driving the market - at least that is the theory most widely accepted.  To do so they have to have a handle on both for your specific inventory.

Specific Considerations       TOP

Before we get to specific considerations, one point needs to be made. The most widely available database of books for price comparison is the Amazon database. It is also the service you see mentioned most often on the net when looking at repricing software for media like books and/or DVDs, etc. Although it does not make a difference in many cases, we will assume that we will be using the Amazon data. Thus we will have available (an approximation to) the “demand for the book”, the Amazon ranking (yes, I know that a snapshot of the ranking just indicates the last time the item sold and not its popularity but we will be assuming that the ranking used is an average over time which does indicate popularity).

A: General Exclusions       TOP

What items are you going to exclude from repricing? Different rules may apply depending on the type of item. For example, don't reprice Records which have been listed less that 2 weeks and don't reprice Books which have been relisted less than a week.

(1a) What is the minimum price you would like to have automatically repriced (value in your inventory currency, typically USD for AoB)? Any price below this will not be repriced, so if you answer 0, all items will be repriced subject to other rules, i.e. see the minimum number of days (3a).

(2a) What is the maximum price you would like to have automatically repriced (value in your inventory currency, typically USD for AoB)? Any price above this will not be repriced, so if you answer 1000000 (larger than your most expensive item), all items will be repriced subject to other rules, i.e. see the minimum number of days (3a).

(3a) What is the minimum number of days the item should be listed before you automatically reprice it? If you have faith in your initial pricing, you might want to wait a bit before you start to automatically reprice the item. If you want to reprice regardless of the number of days listed, use a zero.

4a) What is the maximum number of days listed you quit repricing the item. Never would be 1000000 [actuallly this is only about 2738 years but it should suffice for most purposes].

(5a) What is the minimum Amazon sales rank you would like to reprice (everything with a rank below this will not be repriced)? Some people like to just set a price for fast selling items and forget it because it will sell fairly quickly anyway. Others like to reprice everything subject to the other rules. In this latter case you would use a zero.

(6a) What is the maximum Amazon sales rank you would like to reprice (everything with a rank above this will not be repriced)? Some people like to just set a price for slow selling items and forget it because the item is "worth waiting for the right buyer". Other like to reprice everything subject to other rules. In that latter case you could use 100000000.

(7a) Do you want to exclude any general category from repricing, i.e. Collectible, Used, New, Acceptable, ...? If so, which ones.

(8a)Do you want to exclude certain patterns which occur in your keywords, notes, or private keys or ...? If so, what are the patterns and where do they occur? For example, there may be certain items you would like to always manually reprice. If you entered MRO in private field p0 to indicate this, then your answer would be yes, MRO in private field p0. Note that you are not limited to just a single choice. You could use any or all of your private fields and your keywords and your notes.

B: Determining Comps       TOP

Who/what are you going to price 'against'. You may want the different rules for differnt type items. For example, Records require a minimum feedback of 4.3 and Books require a 4.6. You may not want to consider certain dealers. Note: The more restrictions, possibly the fewer comps you will have.

(1b)What is the minimum feedback rating for a dealer to be considered. The ratings, when given are on a five point scale, so typical answers range from 4.2 to 4.8. IMO, both of these extremes are too low/high.

Note: Amazon has been returning nothing for Feedback ratings. AOB has been setting the feedback rating to zero. So, if the rating is zero or is greater than the following minimum, the dealer's prices will be considered (assuming other restrictions, possibly such as Condition are met).
Do you want to "grade" the dealer on their feed back? That is, if you were comparing prices to a dealer with a feedback of 4.2 and you typically had a 5.0 feedback, you might consider asking 10% more for your item. You want to be careful with this if you are using other tables to convert prices.

(2b)What is the minimum number of feedbacks needed to use a dealers prices? For example, you might not want to include sellers who are "fairly new", i.e. don't have at least 50 feedbacks. Feed backs tend to run somewhere between about 10 and 30 percent on Amazon so, using the average of 20%, a feed back of 10 would translate to sales of about 50 items; a feedback of 50 would translate to about 250 items. Again, this value may not be available for all dealers on AoB so, if the value is zero, the item will be repriced anyway (subject to other rules). Do you want to "grade" the dealer on their number of feedbacka? That is, if you were comparing prices to a dealer with 10 feedbacks and you had several thousand, you might consider asking 10% more for your item. You want to be careful with this if you are using other tables to convert prices.

(3b) Who are the excluded dealers. Certainly you would want to exclude yourself but there may be others you would also like to exclude.

(4b) What is your minimum outlier price?. That is, what is the minimum price to be considered in the computation of a new price? This does not have to be your minimum price for the item. If the dealers price is less than this, his price will not be considered. As an example, you feel that your price should not be compared to items more than 50% down from your price, i.e. if you have an item priced at $10, you don't want to compare it to items less than $5. Then chose a factor of 0.5.

(5b) What is you maximum outlier price?. That is, what is the maximum price to be considered in the computation of a new price? This does not have to be your maximum price for the item. If the dealers price is more than this, his price will not be considered. As an example, you feel that your price should not be compared to items more than three times your price, i.e. if you have an item priced at $10, you don't want to compare it to items higher than $30. Then chose a factor of 3.0 [300%].

(6b)Do you want to compare those in my condition class only (Used, Collectible, New) or some other combination, i.e. you might want New and Collectible to include each other for comparisons but Used would only include Used comparisons.

(7b) Do you want to compare items in your condition, your condition or better, all items, or some other combination? Also see (6b).

(8b)Do you want to consider converting items not in your condition to your condition by making a conversion table? As an example suppose you had the following: Like New was worth 87.5% of a New item, Very Good was worth 75% of a New Item, Good 50% and Acceptable 25%. That would give rise to the following table:

New = 1.000
Like New = 0.875
Very Good = 0.750
Good = 0.500
Acceptable = 0.250
To convert an item to New condition, you divide by the number. That is New is 4 times the price as an Acceptable (divide by 0.250), 2 times the price of a Good item, one and a third times a Very Good item, and 1 and a seventh times a Like New item. An example of the way this table would be used is the following: Suppose you had an item in Very Good condition, so you want comparisons to Very Good items. Also suppose you only had an item in Good condition at $10 to compare to. First convert the Good to a New Item, i.e. twice the Good item or $20. Now convert to a Very Good item, i.e. 75% of $20 or $15. If you would like to use this kind of capability, provide factors for the above table. Also, if you could have different tables for different types of items, say a table for books, one for records, and on for video games.

Do you only want to use the table on particular classes or conditions or ranks or ...

(9b)Are there some dealers you would like to "add a bit" to their prices? For example, a dealer charges a $4.99 Standard S&H on Amazon (obviously a Seller Central dealer) and Standard S&H is $3.99 for you. You might want to add $1 to this dealers prices for a "fair comparison".

C: Limitations on Price Changes       TOP
Limitations on price changes may depend on type of item and/or price and/or ...

(1c) What are your minimum prices, if any, for

New Hardcover: New Paperback (includes Mass Market Paperback & Softcover): Used Hardcover: Used Paperback (includes Mass Market Paperback & Softcover): Oversized/Heavy (and how and where is it designated): DVD/CD: Record: ...

(2c) What is the maximum price drop you want? A value in dollars (or the currency your inventory is priced in).

(3c) What is the maximum price raise you want? A value in dollars (or the currency your inventory is priced in).

(4c) What is the maximum price drop percentage you want? A value of 30% would be 0.3 or 30%.

(5c) What is the maximum price rise percentage you want? A value of 30% would be 0.3 or 30%. Thirty percent would mean, for example, that a $10 book would not be raised higher than $13.

(6c) What happens if the minimum/maximum price drop/raise is reached? One usually just reprices the item at that price. However, you might not want to reprice the item if the price raise were raised to $50 on a $5 book (1000% percentage raise). You might want to actually look at the prices yourself. Note: If you have different answers for (2c) through (6c), please match up the answers with the list number.

D: General Considerations       TOP

(1d)Other things to consider when you are thinking of repricing rules is whether you want different rules depending on the length of time listed and/or the Amazon ranking of the item, whether you want to reprice if there are only a few (less the 3? 2? ...) items listed, whether the number of copies you have should affect your pricing, whether certain items should not have their price lowered (raised), whether you want to lower (raise) an items price twice in a row, ... Note that different rules can be programed for different situations. For example you may want repricing rules based on the Amazon rank and the amount of time listed. Lists B and C above can be modified for individual rules if wanted.

(2d) Repricing rules can be simple (put my price midway between the first and second lowest price) or complicated (if the item has been listed more than 10 days and less than 60 days, compare my price to any conditions within two of mine using the special conversion table of 1, .93, .85, .70, .3. Use the harmonic average of those in my condition if there are at least three comps. If not, take the harmonic average of each condition and use the lowest. Special outlier values are 0.1 and 50. Special min and max price changes of 60%/$5 down, 100%/$100 up. Compare to anyone but myself. ...)

(3d) When thinking of how you want to reprice, i.e. making rules, remember that you also have to know what to do if there are no comps. Most of the time this is just a 'don't reprice'. But you might do like the 'complicated rule' in (2d). That is, if there are none (or not enough) in my condition do something else, etc.

(4d) What is the order of the "rules", i.e. what is most important? For example suppose you want a minimum price of $5 and to be 10% under Amazon. If you check for the minimum price and then check for under Amazon, it is possible to price your item at less than $5 [think of Amazon selling something at $4.99]. If you first check Amazon price and then check the minimum, you may price above the Amazon price.

(5d) Generally history of prices, rankings, quantity available, etc. are not available on AoB. One simple exception comes to mind immediately and that is the length of time the item has been listed but that's about it. However, you can track a few simple things via your price. For example, if it ends in an 9, the price was not changed the last time it was repriced or was an initial listing or is at the minimum price; if it ends in a 8, the price was reduced last time it was repriced; if it ends in a 7 the price was raised the last time it was repriced. You can also add other "codes".

(6d) On AoB, after repricing, i.e. after running SOLOIST, if you go to Manual Repricing Page [Inventory->Reprice Your Books] you can typically see the items which were not repriced. However, there is a flag which can be set in the repricing script which will cause the items(s) to not be displayed on the page(s). If you have some items which you do not want to show up there in any case, you could, for example, enter NMRP in the p0 field and have the script set that flag. You might also want to use the flag if the book were not repriced because it was already at the minimum. Are there any cases where you would like to use this flag?

(7d) Considerations of rank and sales time indicate that fast selling(low Amazon rank) limited quantity items, i.e. used books, should not be priced at the low end of the spectrum but rather in the mid to high end. The reasoning is that those costing less will sell quickly and then yours will sell. Limited experience (not mine) and further consideration indicates this is not true for (near) unlimited quantity items, i.e. new books. If you are in the middle of the pack on price then those below you won't sell out and you will 'never' sell your item. The placement for these 'new' items may be mitigated by description (a better description means you can price higher, a poor description means you should price lower), feedback (if available a higher feedback, relative to your competition, means you can price higher, a lower feedback means you should price lower).

(8d) Other things to consider

  • What if you are the only seller? Would you want a maximum price? And, if that is true, where do you get that price?
  • Should you reprice if you don't really gain anything by it. For example, sellers 3 and 5 have prices of $3 and $5. You are seller 4 and have a price of $4. You use an average repricing rule which would reprice your item at $3.51. Would you want to reprice? How about if it had been $4.50?
  • Do you only want to consider certain sellers?

Repricing Programs/Services       TOP
  • Alibris You have to be a seller on Alibris and belong to their Gold program. Although several years old, the article in the IOBA Standard by Dick Weatherford still has some good discussion on (re)pricing, see The Alibris Pricing Tool

  • AmanPro Listing, (Re)Pricing and Order Management system for Marketplace sellers.

  • APPEAGLE Supported marketplaces and listings Appeagle is available for listings on the eBay.com, Amazon.com and Buy.com marketplace sites. Support for international sites will be coming shortly. Appeagle supports all marketplace listing types, including auctions, variations, fixed price and fulfillment by amazon (FBA).

  • Book Repricer will save any Amazon Pro Seller hours making sure your books/CDs/DVDs etc, are priced correctly.

  • BookTrakker's Grabit Used for comparing current prices to the competition and resetting your price.

  • Fillz: A web based system offering Standard, Premium or Customized accounts.

  • RepriceIt: You're in control with 25 configurable repricing parameters, with unique features such as, Positive Repricing, and the ability to exclude competing sellers with poor Feedback ratings, and many more options.

  • SellerEngine: If you are an Amazon ProMerchant selling books and media, SellerEngine Plus offers the tools and the speed you need to price competitively and keep all your listings up to date.

  • Teikametrics: The proprietary repricer tool allows you to pinpoint and price any Amazon listing inclusive of shipping costs. Customized rules enable you to choose how you compete for sales.

Simple Repricing Script Snippets       TOP

The following repricing script snippets are provided on an "as is" basis. Versions of these scripts are available at some of the repricing services mentioned above.

Repricing scripts should not, in general, directly change your database.

Don't reprice on flag

    if($flag =~ /(NORPRC)/i ){

      $vout->(comment) = "NORPRC flag set. Not repriced/n";

      $vout->(modify) = "n";

Don't Reprice for greater than Min or less than Max price

    if($my_price < $min_reprice || $my_price > $max_reprice){

      $vout->(comment)  = "Less than minimum or greater than maximumn";

      $vout->(comment) .= "repricing price. Not repriced/n";

      $vout->(modify) = "n";


Don't raise price if flag is set

    if($flag && $new_price > $my_price) {

      $vout->(comment)  = "Flag - don't raise price - set. Not repriced/n";

      $vout->(modify) = "n";


Here are some more places to look around our site:

  • Arkham House, Mycroft & Moran, and Fedogan & Bremer Books
    At the request of several of our customers, we started a page for the books of Arkham House and related publishers. We try hard to keep it up to date with news and a list of forthcoming books and a list of those books we have of these publishers - both new and used.

  • Author Web Sites/Fan Sites
    A list of Authors and their websites or fan sites. Unfortunately, I haven't kept up with the sites going out or changing although a recent check with a program showed no broken links. One can hope right?

  • Book Care and other book information
    About Books includes items on Book Care as well as a How to Identify First Editions. It will include links, reviews, and all kinds of other interesting (to us at least) tidbits as we add to it.

  • Book Condition Description
    We use certain "bookseller" terms when we describe our books. Generally, they tend to mean what you think they would mean. For example Fine means basically without faults. The exact meanings behind what we mean are given on this page. As mentioned on the page, book condition is sometimes a subjective "call" by the book seller. We try to be objective, but might (in your opinion) fail. If so, you can return the book for any reason.

  • Book Inventory Programs The question of which book inventory program to use was always coming up on some of the forums I visit so I though I would put down some thoughts here. It is evolving and will eventually try to cover many aspects of inventory management (in the sometime distant future). In the mean time, if you have something you would like to see, let me know.

  • Book Reviews
    A slowly growing list of books we've reviewed. We would be happy to have your comments and, if you like, your reviews (with, of course, credit to you if you wish).

  • Chrislands Book Stores
    Chrislands is the company which hosts our site. We are very happy with them as are their other customers. This page gives links to many of the other Chrisland stores.

  • General Links; Other Book Stores, SF&F References, Detective/Mystery References, etc.
    Well, that about says it all. This is sort of a catch all for links which don't specifically belong anywhere else. Right now (about 6:41 pm Central US time, Oct. 16 2005), there are four sections, Science Fiction & Fantasy, Mystery - Detective, Arts and Crafts, and Book Related Links.

  • Glenn Larsen's Guide to First Editions
    Copied from Books-Rare, the book collector's home Copyright © 1997 by Glenn Larsen. Sadly, the original is no longer available., but we have a copy of it here with some corrections and additions.

  • Glossary of Terms Used in Literature and the Book and Printing Trades
    This page grew out of a request from a customer about book terms, a bookman's glossary so to speak. Now I could have just pointed them to the IOBA Book Terminology but I though it would be nice [and make our site more attractive] if we had a page of our own. Well now we do - at least the start of one

  • Help for on-line book buyers
    We hope this page will help you have a more pleasant on-line book buying experience. It also lists a few other places to get books - If we don't have the book you are looking for, of course :-)

  • IOBA Book Stores
    The Independent Online Booksellers Association, is dedicated to promoting internet bookselling by, in part, "Maintaining and enforcing high ethical and professional standards for our member booksellers, including a Code Of Ethics." White Unicorn Books is a proud member of the IOBA and on this page we list some of the other IOBA stores.

  • Liaden Universe of Steve Miller & Sharon Lee
    This page is for our Steve Miller and Sharon Lee books. It is mainly books set in the Liaden Universe® and has a list of books in that series, including the Chapter Books, as well as a set of references and links to other sites for the two authors.

  • Previously Featured Books
    Featured Books is where we list the books which have been featured on our home page - we may have more about the book than is in the normal catalog listing, so we decided to just keep track of them here. For example, when we featured the Chronicles of Narnia we listed "both sequences". The order in which they were originally published and "the preferred sequence of CS Lewis".

    We also have some special pages for books which are special in some way. It may be that the book itself is special or that a customer asked for more images, so we put up a page for the book. In any case we have these single pages for a particular book:
    • Butters' Richmond Directory 1855
      An interesting directory for 1855.
    • Crystallizing Public Opinion
      Bernays is considered by many as the originator of modern public relations and has been called the "Father of Spin". He was named one of the 100 most influential Americans of the 20th century by Life magazine.
    • Oxford Lectern Bible The Oxford Lectern Bible is a massive edition of the English Bible designed by American typographer Bruce Rogers (1870-1957). It is considered by many to be Rogers' masterpiece, and is recognized along with the other great Bibles, including the Baskerville Bible and the Doves Press Bible.
    • The Principles Of Judicial Proof
      Normally we don't put up our used books as a Featured Book on the home page they don't last long enough to stay here since we generally only have a single copy) but this one is such an absolutely beautiful book I had to put it up. So, of course, I had to build a page for it.
    • Sleeping Beauty, a Special Collectors Edition with illustrations by Dulac
      A page devoted to a special book. The 1910 limited edition of Sir Author Quiller-Couch's The Sleeping Beauty and Other Fairy Tales, illustrated by Edmund Dulac.
    • The Religious System of China
      First published over quite a few years, the initial volume was published in 1892 and the final volume was printed in 1910, The Religious System of China is a monumental work by Jan J M de Groot that "is an attempt at depicting the Chinese Religion as it is really practiced by the nation, and at sketching on a broad scale its influence on Domestic and Social Life. It is the fruit of an intimate contact with the Chinese race for several years." The work also contains a detailed study of China's funerary stelae, and the mythical animals used to decorate them.
    • Slovenly Peter's Story Book
      A classic 'what happens to bad boys and girls' from the late 1800's.

  • Ramblings/Blog/Book Reviews and whatever
    This is really a series of pages consistings of almost anything. On these pages I've written about Medicard Part D, about searching for information on a book on Google and at the Library of Congress, reviewed several books, and talked about the IOBA. No telling what will show up there. I'm sure we'll duplicate information on the rest of the site, but a lot of it will be unique. Hope you find it of interest.

  • Repricing
    A short look at some of the reasons for (semi)automatically repricing your inventory including a few Perl code snippets.

  • Setting Up an Internet Book Store
    An article I wrote for the IOBA. It presents a "first look" at some of the things one should think about in setting up an internet book store.

  • Transfer Homebase data to BookTrakker
    We use BookTrakker for maintaining and updating our main database of books we have listed here on our site. In talking to other BookTrakker users, they wanted to know how they could use someone to enter data which they could transfer to BookTrakker either in addition to or instead of using the network version of BookTrakker. Since we use both the network version and Homebase as "auxillary input systems", I though I would finally describe how we did the Homebase to BookTrakker part of it.

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