Rick; Sometimes different buyers are viewing a particular chip on ebay for the first time. I know for myself, I have missed out on chips because I'm not near a computer or unable to bid on many weekends, from late Friday afternoons to Monday when I'm in A.C.

Or; maybe this month, money is tight and bidding on ebay is not a practical thing to do in someone's economical situation. Next month, or months later, the chip someone previously decided to do without at a lower price, is now affordable ... even at a higher price. You'll go nuts trying to figure out why similar chips sell for more or less money on different ocassions.

Another factor is condition. The chip that sold for double the amount of its predecessor, may have been in considerably superior condition. That's why one can't say, such and such a chip sold for "X" on ebay and make that the market price. It's no different than two dealers having the "same" chip for sale at the annual convention or local chip show ... at a significant difference in price. Maybe one chip simply happens to be in better condition than the other. Also, there is no universally accepted guide that mandates all dealers should price their merchandise at the same price. Have you been to a used car lot recently?