Those are good questions. One way to find out is by carefully reading the higher priced listings, especially listings by dealers who are ABAA members. An ABAA designation still inspires a certain degree of confidence.
Conversely, don’t be misled by sellers who place absurd prices on what your research shows to be more common wares.
Then look how many copies are really listed. Are there over a 100 different copies available? Or, are there really only six copies, but each one listed in a dozen different places? On ADDall you can tell at a glance.
But, ADDallonly tells you what’s listed. It doesn’t tell you what sold or the selling price or how recently.
Next go to eBay and do a search of “completed items” using a variety of key words Search for something that’s identical or close to identical to what is in your hand. Search for look-alikes with good clear photos. Don’t just search in “books,” because “books” is not always the best category to either buy or sell. Search “all categories.” EBay completed items only go back a few months, but that’s far enough to determine if there are a lot of other competing items and interest and success generated.
Americana Exchange the Most Reliable
Finally, do you have a hunch it might be worth north of $100? If that happens frequently subscribe to the Americana Exchange data base.
Americana Exchange is the best, most complete and most reliable estimation of current market value in the book world today. Americana Exchange auction records search (a by- subscription feature) will surface prices realized, comparables, frequency and condition. It’s not infallible, but it is reliable. In a world filled with hype and guess work it’s a very good deal, especially if you’re a seller.
The combination of those three searches will usually result in a fair estimate of current market value.
But sellers don’t just want to get the current market value, they want to get more. Not surprisingly, sellers want top dollar.
Start High
I was fortunate to be born into the antiquarian book business a long time ago and to learn the trade from my parents who were ABAA dealers for 50 years. From my wise elders I learned it is easier to come down from a high price than to go up from a low one.
So a lot of times - no matter what the research says - I will pick a starting price that is, to put it kindly, “optimistic.”
I also learned from my folks that if it’s yours and you only have one copy, it doesn’t matter what the auction records say, or how many copies are listed, all you really need is one (1) buyer who is willing to pay your price.
Swann Maps & Atlases, Natural History & Color Plate Books December 9, 2025
Swann, Dec. 9: Lot 156: Cornelis de Jode, Americae pars Borealis, double-page engraved map of North America, Antwerp, 1593.
Swann, Dec. 9: Lot 206: John and Alexander Walker, Map of the United States, London and Liverpool, 1827.
Swann, Dec. 9: Lot 223: Abraham Ortelius, Typus Orbis Terrarum, hand-colored double-page engraved world map, Antwerp, 1575.
Swann Maps & Atlases, Natural History & Color Plate Books December 9, 2025
Swann, Dec. 9: Lot 233: Aaron Arrowsmith, Chart of the World, oversize engraved map on 8 sheets, London, 1790 (circa 1800).
Swann, Dec. 9: Lot 239: Fielding Lucas, A General Atlas, 81 engraved maps and diagrams, Baltimore, 1823.
Swann, Dec. 9: Lot 240: Anthony Finley, A New American Atlas, 15 maps engraved by james hamilton young on 14 double-page sheets, Philadelphia, 1826.
Swann Maps & Atlases, Natural History & Color Plate Books December 9, 2025
Swann, Dec. 9: Lot 263: John Bachmann, Panorama of the Seat of War, portfolio of 4 double-page chromolithographed panoramic maps, New York, 1861.
Swann, Dec. 9: Lot 265: Sebastian Münster, Cosmographei, Basel: Sebastian Henricpetri, 1558.
Swann, Dec. 9: Lot 271: Abraham Ortelius, Epitome Theatri Orteliani, Antwerp: Johann Baptist Vrients, 1601.
Swann Maps & Atlases, Natural History & Color Plate Books December 9, 2025
Swann, Dec. 9: Lot 283: Joris van Spilbergen, Speculum Orientalis Occidentalisque Indiae, Leiden: Nicolaus van Geelkercken for Jodocus Hondius, 1619.
Swann, Dec. 9: Lot 285: Levinus Hulsius, Achtzehender Theil der Newen Welt, 14 engraved folding maps, Frankfurt: Johann Frederick Weiss, 1623.
Swann, Dec. 9: Lot 341: John James Audubon, Carolina Parrot, Plate 26, London, 1827.
Sotheby’s Book Week December 9-17, 2025
Sotheby’s, Dec. 11: Darwin and Wallace. On the Tendency of Species to form Varieties..., [in:] Journal of the Proceedings of the Linnean Society, Vol. III, No. 9., 1858, Darwin announces the theory of natural selection. £100,000 to £150,000.
Sotheby’s, Dec. 11: J.K. Rowling. Harry Potter and the Philosopher's Stone, 1997, first edition, hardback issue, inscribed by the author pre-publication. £100,000 to £150,000.
Sotheby’s, Dec. 11: Wolfgang Amadeus Mozart. Autograph sketchleaf including a probable draft for the E flat Piano Quartet, K.493, 1786. £150,000 to £200,000.
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.
![<b>Sotheby’s, Dec. 11:</b> Darwin and Wallace. On the Tendency of Species to form Varieties..., [in:] <i>Journal of the Proceedings of the Linnean Society,</i> Vol. III, No. 9., 1858, Darwin announces the theory of natural selection. £100,000 to £150,000.](https://ae-files.s3.amazonaws.com/AdvertisementPhotos/00d5fd41-2542-4a80-b119-4886d4b9925f.png "<b>Sotheby’s, Dec. 11:</b> Darwin and Wallace. On the Tendency of Species to form Varieties..., [in:] <i>Journal of the Proceedings of the Linnean Society,</i> Vol. III, No. 9., 1858, Darwin announces the theory of natural selection. £100,000 to £150,000.")
