It's a good question: With Pricebenders you need of patiente and you must to be lucky.You must also to observing the time do you usually see auction, who are the the bidders that usually wins, the number of bidders observers this aution and how valuable the auctioned item.
Also consider that every time you bid you have already won 2 things, that's MRP and VP.
So the very key on winning the auction is participating! Good luck for all!!!