Well, in my 4-year experience with eBay I have had almost everything, like most of you.
I've tried many strategies but I will tell you the one that works best, though you will be disappointed: I bid to my maximum as soon as I see the item I'm interested in, or if the item is commonplace I wait until the last two days just in case a better or cheaper one pops up.
I've discovered that last-minute bidders will bid above their own maximum just to win the auction, because having waited for seven days and giving up in the last minute is some kind of defeat. If I'm genuinely interested I bid to my maximum, and let less-interested bidders to bid and be outbid by my bid three or four times. Sure, they are jacking up my price, but when you are outbid four times and you don't know how much is the other buyer's maximum bid, you just forget about it and search a new one. If the price gets reasonably high two or three days before the auction ends, it discourages snipers because there is no chance to get a bargain, and you are always in time to pay a fair price for an article. I won't loose any sleep -literally- to win any item, just bid to my maximum.
A month ago I forgot to bid in a book that sold for about 15 bucks, when it has been being sold for 50 bucks. The next one that appeared sold for $52 -I withdrew at 32-, but yesterday night I won one for 26 bucks. Fair enough, it just takes time. The difference? The first time I waited till the last hours and couldn't make it home on time, last night I put my bid with days in advance, but I can tell you that my maximum bid was just 50 cents above the winning price. One bid more and I would have been outbid. No problem, I'm always in time to pay a ridiculous price, but I will just put a reasonable bid.
Raul