When bidding for diecast, don't bid against yourself. Know what you are bidding on, what it is worth  and what is the MAX you will pay for it. Once you have placed your bid, stick with it. There are other bidders out there that will try to run the price up by repeat bids and you will end up basically out bidding yourself. Then you dont end up winning the car anyway. This approach will keep prices reasonable and help you to have a better chance of winning the auction.