i am selling a very expensive laptop on ebay at auction, with a buy it now option. Someone has offered the starting price(without putting in a bid) I declined as there are many watchers. Hes has come back a couple of days later asking "how much?" I replied...as per auction. Now discovered he has only been an ebay member for 3 months and has zero feedback. Should I/can I prevent him from bidding. Worried about all the scams revealed on here. Thanks for any advice.