Optimistic pricing happens for other collectibles, too. A friend of mine has been a collector of LP's and 45's since the '70's. He says he runs into people all the time who think their copy of, e.g., Elton John's Goodbye Yellow Brick Road must be valuable, but there are millions of copies out there in thrift stores and elsewhere.

A few years ago, he bought some 45's at a swap meet near his house, including three copies of something called Booze Party, by Three Jacks and an Ace. (Look it up. It's a cool rockabilly song.)

He put two of them up on eBay. Bidding war between a guy in England and another in Germany. The first sold for $950 and the second for $1,100.