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

  • ALDE, Apr. 8: GUEVARA (ANTONIO DE). Histoire de Marc-Aurèle, Empereur Romain, vray miroir et horloge des Princes. Paris, Pierre et Galliot du Pré, frères, 1565. €3,000 to €4,000.
    ALDE, Apr. 8: HEURES DE LA VIERGE. Horæ in laudem beatissimæ virginis Mariæ ad usum Romanum. Paris, Charles L'Angelier, 1556. €4,000 to €5,000.
    ALDE, Apr. 8: MONTAIGNE (MICHEL DE). Les Essais. Édition nouvelle, trouvée après le deceds de l'autheur… Paris, Abel L'Angelier, 1595. €6,000 to €8,000.
    ALDE, Apr. 8: [ROJAS (FERNANDO DE)]. Celestina, tragicomedia di Calisto et Melibea, tradotta de lingua castigliana in italiano idioma… Venise, 1531. €2,000 to €3,000.
    ALDE, Apr. 8: CAMÕES (LUÍS DE). Os Lusiadas. Lisbonne, Pedro Crasbeeck, 1613. €2,000 to €3,000.
    ALDE, Apr. 8: CERVANTES (MIGUEL DE). El Ingenioso hidalgo Don Quixote de la Mancha. Bruxelles, Roger Velpius & Huberto Antonio, 1611. €6,000 to €8,000.
    ALDE, Apr. 8: LA FONTAINE (JEAN DE). Fables choisies, mises en vers. Paris, Denys Thierry et Claude Barbin, 1678-1694. €6,000 to €8,000.
    ALDE, Apr. 8: CERVANTES (MIGUEL DE). El Ingenioso hidalgo Don Quixote de la Mancha. Madrid, Joaquin Ibarra, 1780. €3,000 to €4,000.
    ALDE, Apr. 8: DIDEROT (DENIS) ET JEAN LE ROND D'ALEMBERT. Encyclopédie, ou dictionnaire raisonné des sciences, des arts et des métiers. Paris, 1751-1765. €15,000 to €20,000.
    ALDE, Apr. 8: [LIVRE TISSÉ]. LAMARTINE (Alphonse de). Les Laboureurs. Poème tiré de Jocelyn… Lyon, J. A. Henry, 1883. €8,000 to €10,000.
    ALDE, Apr. 8: [LIVRE TISSÉ]. Livre de prières tissé d'après les enluminures des manuscrits du XIVe au XVIe siècle. Lyon, [A. Roux], 1886. €5,000 to €6,000.
  • Sotheby’s
    Books, Manuscripts & Objects from Three Important Collections
    Open for Bidding 2-17 April
    Sotheby’s, Apr. 2-17: [Guillaume de Lorris and Jean de Meun]. Le Roman de la Rose, [Geneva or Lyons, c.1481], first printed edition of the most important medieval French vernacular poem. £200,000 to £300,000.
    Sotheby’s, Apr. 2-17: Castiglione. Il libro del cortegiano. [Venice], April 1528, first edition, in a magnificent binding by Jean Picard for Jean Grolier. £100,000 to £150,000.
    Sotheby’s, Apr. 2-17: Jacobus de Cessolis. Schachzabelbuch, Strasbourg, 1483, von der Lasa copy. £50,000 to £70,000.
    Sotheby’s, Apr. 2-17: World Championship, 1972. A collection of 84 press photographs of the famed match between Spassky and Fischer. £2,000 to £3,000.
    Sotheby’s, Apr. 2-17: Ben Franklin. Autograph letter signed, to Lord Shelburne, British Prime Minister, during peace negotiations, November 1782. £15,000 to £20,000.

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