I was actually a power seller on ebay for a while, but tapered off on my listings for a while so they took my power seller status away. But I didn't have to many problems with non-paying bidders, partly because I was pretty clear about the merchandise I was selling, and partly because I won't hesitate to file a non-paying bidder alert on someone. If they get two they are suspended for good from eBay. I'm sure most of you are thinking, "well, why would'nt they just start a new account". And the reason is, eBay collects quite a bit of info on you, and you would have to go to quite a bit of trouble to open a new account. You would have to open it under a new name, and you would have to have a credit card on file for that name. A new paypal account, and a new email address. Not to mention, it is a pain to get your feedback numbers high, starting over would just suck. I used to also write in my ad that, no bidding unless you have at least 10 feedbacks, and none of them negative.