A-Best: They will charge you whatever your winning bid is plus shipping. I think you need to read how bidding works!
In case you haven't heard new policies are going into effect today which you might want to check out before using ebay. Thousands of buyers and sellers are boycotting and searching out alternative sites.
See the video that explains it all
"Feb 18-25th 2008: Worldwide Ebay Strike"
http://www.youtube.com/watch?v=23TomS5--nQ