Auction fever...
Landric--It happens at "real" auctions, too. I've gone to several of those where 2 or more bidders just went nuts against each other, and the final price for an item was just astronomical.
When my parents-in-law sold out of dairy-farming we lucked in on the GREAT side of that. It was a beautiful day, and the auction was well advertised. The guys buying the cows bid like those were the last cows ever to be sold. There were collectors fighting over my FIL's elderly tractors--and the 2 decent tractors went well, too. The Amish guys from down the road wanted all of his pull-behind equipment. There were antique collectors who bought almost anything old, dirty, and rusty, from the basement.
The ultimate was a pile of rusty junk. Literally. I know, I piled it. Bent steel fence posts, broken iron castings, ruined fenders off long-dead trucks, etc. All the steel junk that accumulates on a farm. Nothing but scrap iron. Two guys bid it up to a point where I actually asked the auctioneer to call a halt, and pointed out to them that it was ALL rusty old junk. The response? "Let us bid, let us bid!" One of the guys beat out the other, and paid up, and gleefully hauled it all away. Ye gods.
When you're the seller, "Auction Fever" is a wonderful thing!
The ONLY way to make out at an auction is to know your prices, pick a "top bid," and stick to it.