A couple of weeks ago I was selling some light shades that I bought in IKEA, as I no longer needed them. The second hand ones that I was selling were going for more than brand new ones in IKEA - I love it when that happens!
It's often the case when people get carried away. Many times I've had auctions like that, sometimes a moment of doubt appears whether there going to pay up when they realise how much they've bid.
One time, when I tried to sell my old CD player, it happened. I have bought it for some 100$, but on the bid also I got same. Any way I got money back without problems.
I have had similar experiences such as a Dell DJ mp3 player I sold for $35 more than I paid for it from Dell 8 months prior.
If the people had checked the Dell site regularly they could of gotten it new on sale for cheaper the next week. As long as they believe they got a deal then life is good.
I've heard that for some people it's like a contest, and they have that competitive drive to win. It seems silly to me, because I wouldn't associate overpaying with winning.