The minimum amount you can bid is shown when you click "Place Bid". The minimum bid is the current bid plus the next bid increment.
You can also set a higher maximum bid. Setting a maximum bid higher that the minimum bid means we will automatically bid again for you if you are outbid. Your maximum bid is always private and not shown to other bidders.
For example, if the minimum bid is $10 and you set a maximum bid of $14, your bid will be $10. If another bidder places a bid of $11, we will automatically increase your bid to their bid plus the bid increment to $12. Then if somebody bids $13, your bid will increase to $14. Since your maximum bid has now been reached, we will not automatically bid for you again unless you set a higher maximum bid.