Rare Book Monthly

Articles - August - 2007 Issue

AE Services Part 3: Current Price Estimator

AE Price Estimator shows upward value trend for a Gutenberg Bible leaf.

AE Price Estimator shows upward value trend for a Gutenberg Bible leaf.


By Michael Stillman

This month we look at one of the Americana Exchange's most useful tools, its current price estimator. It updates values of prices in the 1.6 million-plus AE Database (AED) of book records to their current estimated value. It helps you make sense out of old priced records, those which go back as far as 1914. This tool comes with all subscriptions to the AED, which contains over 1.6 million book records from auctions, catalogues, and bibliographies, most of which include prices.

Here is how it works. The AE price estimator takes a price from any given year and updates it to 2007 values, based on typical increases in book values since that year. For example, the average book value has increased fivefold since 1980, fifty times since 1936. So, the current price estimator will take a book that sold for $2 at auction in 1936 and provide a current estimate of around $100. If a book has sold multiple times since 1914, it will provide a current estimate for each year's price, and even average out all of those estimates for a cumulative current estimate for all sales combined.

How accurate is this? We certainly would not claim these are definitive values. The rate of increase is based on what we have seen across the broad spectrum of records within the AED. Therefore, they represent the overall trend in pricing. However, not every book has appreciated at the average rate. In general, the rarest and most historically important texts have appreciated at an above average rate. On the other hand, some fiction and poetry that was popular years ago, but has since fallen out of favor, has stagnated while the world around it rushed forward. What these numbers most clearly do is convert the price the book sold for years ago into today's book dollars. On average, that is the same as current value, but can vary for individual items.

Fortunately, most books appear in the AED multiple times, providing several looks at its value. The averaging feature is very helpful here. Also, looking at price trends based on current estimates is very useful for understanding value. If more recent sales translate to higher current estimates than older ones, this is a good sign that the book is appreciating at a higher than normal rate. It may be a better investment than a book trending in the other direction. Naturally, more recent sales are likely to provide estimates closer to current value than ones from the distant past. Nevertheless, this tool will place even those oldest records into sufficient context to be meaningful.

Obtaining pricing data is one of the most difficult challenges for sellers and buyers alike, yet it is undoubtedly the most important item of practical information each needs. Few collectors can afford to seriously overpay, while sellers don't want to undercharge or price so high they cannot sell. Many people look to online listing sites such as Abebooks for pricing information. The problem with this is that Abe values are asking prices, not selling ones. Often, someone will post a price pulled out of thin air, and then others will follow like lemmings with similar figures. Those books can stay unsold seemingly forever, all sellers locked in to the first posted, unrealistic price. In other situations, prices for similar items can be all over the place, one seller wanting $10, another $100. What is this book worth? Who knows? None of these represent actual sales, and it is not clear which, if any, prices were posted by knowledgeable sellers versus rank amateurs.

Rare Book Monthly

  • Bonhams, Dec. 8-18: Autograph Letter Signed ("Martinus Luther") to His Friend the Theologian Gerhard Wiskamp ("Gerardo Xantho Lampadario"). $100,000 - $150,000.
    Bonhams, Dec. 8-18: An Exceptionally Fine Copy of Austenís Emma: A Novel in Three Volumes. $40,000 - $60,000.
    Bonhams, Dec. 8-18: Presentation Copy of Ernest Hemmingwayís A Farewell to Arms for Edward Titus of the Black Mankin Press. $30,000 - $50,000.
    Bonhams, Dec. 8-18: Autograph Manuscript Signed Integrally for "The Songs of Pooh," by Alan Alexander. $30,000 - $50,000.
    Bonhams, Dec. 8-18: Autograph Manuscript of "Three Fragments from Gˆtterd‰mmerung" by Richard Wagner. $30,000 - $50,000.
    Bonhams, Dec. 8-18: Original Preliminary Artwork, for the First Edition of Snow Crash. $20,000 - $30,000.
    Bonhams, Dec. 8-18: Autograph Letter Signed ("T.R. Malthus") to Economist Nassau Senior on Wealth, Labor and Adam Smith. $20,000 - $30,000.
    Bonhams, Dec. 8-18: History of the Peloponnesian War by Thucydides Finely Bound by Michael Wilcox. $20,000 - $30,000.
    Bonhams, Dec. 8-18: First Edition of Lewis and Clark: Travels to the Source of the Missouri River and Across the American Continent to the Pacific Ocean. $8,000 - $12,000.
    Bonhams, Dec. 8-18: Original Artwork for the First Edition of Neal Stephenson's Groundbreaking Novel Snow Crash. $100,000 - $150,000.
    Bonhams, Dec. 8-18: A Complete Set Signed Deluxe Editions of King's The Dark Tower Series by Stephen King. $8,000 - $12,000.
    Bonhams, Dec. 8-18: Autograph Letter Signed ("John Adams") to James Le Ray de Chaumont During the Crucial Years of the Revolutionary War. $8,000 - $12,000.
  • Sotheby’s
    Book Week
    December 9-17, 2025
    Sotheby’s, Dec. 12: Hooke, Robert. Micrographia: or some Physiological Descriptions of Minute Bodies made by Magnifying Glasses. London: James Allestry for the Royal Society, 1667. $12,000 to $15,000.
    Sotheby’s, Dec. 12: Chappuzeau, Samuel. The history of jewels, first edition in English. London: T.N. for Hobart Kemp, 1671. $12,000 to $18,000.
    Sotheby’s, Dec. 12: Sowerby, James. Exotic Mineralogy, containing his most realistic mineral depictions, London: Benjamin Meredith, 1811, Arding and Merrett, 1817. $5,000 to $7,000.
  • Heritage Auctions
    Rare Books Signature Auction
    December 15, 2025
    Heritage, Dec. 15: John Donne. Poems, By J. D. With Elegies on the Author's Death. London: M[iles]. F[lesher]. for John Marriot, 1633.
    Heritage, Dec. 15: Edgar Rice Burroughs. Tarzan of the Apes.
    Heritage, Dec. 15: F. Scott Fitzgerald. Tender is the Night. A Romance.
    Heritage, Dec. 15: Bram Stoker. Dracula. Westminster: Archibald Constable & Co., 1897.
    Heritage, Dec. 15: Jerry Thomas. How to Mix Drinks, or the Bon-Vivant's Companion, Containing Clear and Reliable Directions for Mixing All the Beverages Used in the United States…
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