This has happened to me several times. Or, a seller will offer 10 of the same item on separate auctions, and it's been something I've really wanted. I don't want to lose out or pay more than another auction winner, so I wonder if I should bid on more than one auction and risk having to buy both, if I win.
You might just be okay though....I usually wait til the last few seconds to bid and I know others do the same.