During an auction-style listing bids are placed by potential buyers, in turn the system automatically calculates the bid increments and raises your bid to maintain your position as the high bidder or to meet the item’s reserve price, up to the maximum amount you entered.
How are the bid increment amounts calculated?
Bid amounts are increased following a pre-set chart, see below. Incremental amounts are based on the current high bid on the item.
Reserve price auctions are unique in the sense that the seller has opted to set a minimum price to sell his item. If your bid meets or exceeds this amount it will be raised to the reserve price right away and the bidding will continue from there. Your maximum bid will never be exceeded.