That's not to say that these sites cannot be at all helpful as pricing guides. For one, the lowest price offered will, in most cases, tell you the upper end of market value. It just stands to reason. If someone is willing to sell for that price, but there are no takers, the market is certainly not higher. The exception would be if the book sells quickly, indicating it might have been underpriced. If it hangs around for long, the market price may be lower, but it almost certainly isn't higher.

The online sites are most useful for inexpensive material. They can tell you something if one book has a low price of $1, versus $10 or $20 for another. Books in this price range are unlikely to have been valuable enough to have made it to auction or most booksellers' catalogues anyway, so this is probably the only pricing information available. However, when it comes to rarer and more valuable items, online pricing swings wildly and incoherently, and you are more likely to make wrong decisions than right ones based on bad information. Garbage in...

This new pricing tool is now available to all subscribers of the AE Bibliographic Database. This database includes hundreds of thousands of priced historical records, along with continually updated listings from virtually all major worldwide book auctions to provide current pricing. The pricing charts you see with this article can be created for any title in the database with the click of a button. While we can't quite offer the AE Database for free, the price remains surprisingly cheap. It was a remarkably good value for all of the information it provides even before the addition of this pricing tool. The added price for including this tool is zero, and all current subscribers will gain immediate access with no additional charge. The database and pricing tool come with all paid memberships, even the least expensive level (Research) or the one-week trial (Visitor). To see the pricing or to sign up, go to www.americanaexchange.com/NewAE/registration/becomeamember.asp.

And now to answer our quiz: the average book which sold for $5 in 1955 will sell for around $135 today. Books have almost always outperformed the Consumer Price Index, except for brief periods when prices temporarily receded. Comparison to the stock market is more interesting. For books/stocks purchased and held until the present, using the Dow Jones Industrial Average for comparison, the 1950s and 1960s were stronger for purchasing books, partly because a soft book market in the early 1950s held prices down. However, the long decline and stagnation of the stock market in the 1970s made stocks the better investment on average starting around the middle of that decade. The advantage did not swing back to books until the late 1990s, when the "bubble" led stocks to climb to unsustainable levels.