I am unclear on the bidding system in the AH. It says current bid and at the end of the auction I bid above that number and it says you lose you were not the highest bidder.
Example :
Mike bids 500 => the price is set to 1, Mike is the highest bidder.
Joe bids 1000 => the price is now 501 and Joe becomes the highest bidder.
Ted bids 750 => the price is now 751 and Joe stays the highest bidder.
That also means you can freely bid the maximum price you are ready to pay.
Example: you bid 1000. If no one else offers more than 500, you will pay only 501.