I tend to bid early, or at least not late. I don't want to play games with timing, psyching out other bidders, etcetera. I bid the price at which I would be indifferent about whether I get the product* or lose out to someone else**, and leave it at that.
Waiting until the last minute to bid seems to me to be playing a game of, "if I withhold my valuation, maybe nobody but me will realize the true value of this item." I think it's a false game. If there are other bidders, they have access to the same information I have. They will put their own value on the item, and either value it higher than I do or not.
If someone feels compelled to outbid me in order to "beat" me and not because that's the value s/he would have put on the item in the first place, then fine, they can have the auction. If the urge to beat me takes some money from the bidder's pocket and puts it in the seller's pocket, that's all right with me; I have nothing against sellers.
If someone gets less fun out of sniping because I've already placed a bid higher than their hoped-for bargain price, that's okay with me; I think sniping is rude and am not motivated to maximize the fun for those who practice it.
If my early bid means that I myself might conjecturally wind up paying a higher price than I would have if I'd been cagier with my bidding, that's okay with me too; I bid a price that I could live with, and as I said before, I have nothing against sellers.
[size=xx-small]* "Hooray."
** "At that price I don't mind waiting for the next one."
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