I remember the first time I sold anything on Ebay. It was a k6-300 that I bought for $42 incl shipping. It turned out to be incompatible with the motherboard I had (DOH!!), so I auctioned it. Sold it for somewhere around $55, plus shipping!
For weeks after that, I continued to receive emails from people asking me if I had any more to sell. One guy offered to pay $60 plus shipping if I did. I directed him to pricewatch, where the same merchant I bought mine from was advertising it for $37 incl shipping.
I'd be willing to bet these are the same people that pay AT&T's $.35/min basic rate for long distance.