The result is we have to turn to Economics 101 instead of a price guide to figure a book’s value. In other words, it’s back to supply and demand. However, this is tricky when quantities are so small. The price of bread is determined by the balance of millions of loaves for sale with millions of people wanting to buy bread. For old books, the balance between buyers and sellers is determined by only a handful. In fact, it may be as low as 1-0, one copy for sale but no wants it, or no copies for sale but someone desperately wants one.

That can create wild swings and price anomalies. But more likely, there will be 5 or 10 or 20 copies now visibly available, and both buyers and sellers are going to have to determine what the market will bear.

So let’s go back to that book with 20 copies available online, for which the prices might range from $20 to $200. Which price is “right?” First, you need to check condition and consistency. Condition can be a little difficult, since not everyone is using the same standard. Experienced, reputable dealers will likely describe condition similarly, but the internet is filled with amateurs who may mis-describe a book more out of ignorance than dishonesty. You will have to show some caution, and be sure that the book can be returned if not accurately described.

Consistency means making sure that various copies offered are actually the same. Are the edition, date, printing location, etc. all the same? This is the easy part. Next, are any parts missing? I have in front of me a copy of Howard Stansbury’s 1852 An Expedition to the Valley of the Great Salt Lake…and Two Large and Accurate Maps of that Region. Note the last part of what is an exceedingly long title, which appears in very small print on the title page. I did a little digging in the bibliographical records in the Americana Exchange Databaseand found that there were indeed two loose maps that came with this book. I don’t have them and I doubt that many other copies still have them intact. Still, of all the listings that appeared on Abebooks, only one seller seemed to be aware of this issue and pointed out that the maps were missing. A copy that has them would be worth substantially more, but it’s impossible to tell from the other descriptions which if any include the maps and the added value that goes with them.

Once you have determined the copies are consistent, and from the descriptions the condition sounds comparable, which price is right? If you’re a seller, you would like to think the highest one, but you don’t get to choose. You have to wait for a fish to bite. What if you are a fish? Is the old adage “you get what you pay for” right? Is that $200 copy clearly superior and more valuable than the $20 one?