When it comes to eBay, I look at the item. I think to myself "how much do I want to pay for this item?" then enter that amount. Sometimes, I get an email back telling em I now own a coffee table or somesuch, and other times, I don't. When I don't, someone thought the item was worth more than I did, so they bought it. On occasion, I'll even send a message to a seller offering them £X if I can pick it up tomorrow, before the auction has ended. It is just a way of buying and selling things, so no need, in my mind, to ever get upset over it.