eBay Madness

Why is it that on the rare occasion I actually find something on eBay that I want, I bid what I think is a fair price for the item, only to be outbid by somebody who obviously wants to overpay? I usually research the item I bid on, some I even track recent prices for, so I know what the market is.
Maybe some people have this need to win at all costs. It's the competition of the times. People hunched over keyboards, trying to outdo each other by putting money down as if to say "I want this more than you, so I'll spend more than it could ever be worth in this lifetime!"
That's okay, I'll bid on it today and if I don't get it, I'll wait for the next one!