Hello 'birdman',
This happens because no one has bid higher than 7.99, leaving you at 8.49. Meaning if no one else bids at all by the end of the auction (doubtful), all you would pay would be the 8.49. It is the automatic bidding system, whereby ebay doles out little smidgens of your max to keep you in the lead, - until someone bids more than your $30. Have a look at this link about ebay bidding, - it's short & easy, and explains how it works:
http://pages.ebay.ca/help/buy/automatic-bidding.html
You will find links on the right about bid increments:
http://pages.ebay.ca/help/buy/bid-increments.html
and all about getting outbid, as that one seems to trouble new ebayers the most:
http://pages.ebay.ca/help/buy/outbid.html
Hope you win the auction. 🙂