It's against the rules to end the listing in order to sell outside of eBay, but if you wanted to, since there are no bids as yet, you could revise the start price to $450 and allow the buyer to place a bid for that amount, then either let the auction run its course, of end the listing and sell to the current highest bidder (note that a 9.9% final value fee will be payable on the final sale amount, including postage).