It's called Get it Now (GIN for short). You can set an amount of points you want and a bidder can just click the button that will show up and buy it immediately at the amount you set- it's quicker and sellers can usually get more points for the item that way. If no one has bid yet you can still 'edit' the auction and put one, or you can put one when you first list an auction. Once a bid is placed though you can't unfortunately.