Someone has probably placed a much higher bid and each time you bid it goes 1 higher until it reaches that persons bid. Let's say someone placed a 1000 credit bid but the current bid shows 501, well each time someone bids that person who placed the 1000 credit bid causes the amount to increase until it reaches that amount. This ensures that the other person doesn't out bid them. Best of luck and thanks for bidding. alfreida1