Entering a maximum bid is easy...
Place a bid higher than the asking or current bid, and your maximum bid will be registered.
It is not possible to outbid your OWN bid amount.
Only if someone else has placed a higher bid, or if someone else bids at the same time will the bid amount change.
We highly encourage the use of the MaxBid feature so that you don't miss out on any opportunities to increase your bids close to the end. The MaxBid feature bids on your behalf without your intervention, and other bidders cannot see your maximum bid. Subject to your secret maximum bid, the software is programmed to bid only as much as necessary for you to win the goods.
To change your maximum bid, simply enter a new amount that is at least the current bid amount (you can lower your MaxBid bid to the current price. You can increase it again by just bidding a higher amount).