With Auction Sniper, you can adjust the number of seconds before the end of the auction to bid. The set # is 7 seconds, but you can lower it. The danger of lowering is that if there is interference or too much traffic, it might get there too late. I love AuctionSniper because I put my walk-away figure in and then just put it out of my mind. That way you don't get in frenzy and pay too much at the last minute.
If there are several lots of the thing you want, you can also set up a bidding group on AuctionSniper, and set the price for each item. It will bid on each until you win one, and then stop bidding.