Terry Smart":1n4xmmtw said:
The other people involved.
Bidders are not entirely rational. If my max bid is £10, and I put that bid in three days before, the other bidder(s) have plenty of time to chip away at it. The other bidders will put in a bid for £3, then when they still outbid, a bid for £5, then £7, then £10.50 and it's gone beyond what I'm prepared to pay. Look at bidding wars, that is exactly what many people do, they bid in increments until they are "winning" the auction (actually no such thing, they are just the current high bidder, but that is how many bidders think, or at least behave). It's a bit irrational, but that is the way it is.
If you stay out of it until the very end, that guy sticks his first bid in of £3 and thinks of himself as the "winner" because he sees no-one coming in to challenge it. Whack in the max bid of £10 at auction end, and he has no time to retaliate - and you get the item for £4.
It only works because many people do not actually put in the maximum they are actually prepared to pay, because they don't think hard enough about the real value to them until they are no longer "winning" the item. And many people don't really get the auction process, they want it to work like a physical auction where the bidding carries on in competing increments until there's only one bidder left bidding. Because ebay auctions are ended by the time limit, not the other bidders dropping out, it doesn't work that way.