To enter a MaxBid, simply place the amount you’d like to bid in the bid box, and your MaxBid will be registered. Only the lowest increment will be shown, but you will still hold your MaxBid as the highest bid you’re willing to place. It is not possible to outbid your own bid.
For instance, if an item is currently going for $2, you can put a MaxBid of $10. The system will take the $3 minimum increment, and only when someone bids $4 will your bid of $5 will be placed. If the bidding does not go above $5, you will receive the item for $5. The maximum bid will only be placed if someone else bids higher than your $10 MaxBid.
Your MaxBid is also secret! Nobody else bidding knows you’ve placed a $10 maximum on the item. We highly encourage the use of the MaxBid feature so that you don't miss any opportunities to increase your bids close to the end of an auction. This feature bids on your behalf without your intervention, and other bidders cannot see your maximum bid.
To change your maximum bid, simply enter a new amount that is at least the current bid amount (you can now lower your bid to the current price. You can increase by just bidding a higher amount). Please read more [here]
Have a wonderful day.