Yeah, in a case like this Ebay may actually contact the bidders and see if they're the sellers brother jacking up the price. It's pretty fishy to be over $4k with a week left to bid. Once they get you under their microscope you'd better be careful with "buddy bidding". Really ebay smart folks can probably get away with it but you'd better be smarter than they are or else you're all banned and the item will be taken down.