i'm willing to go to freelancing site, but i prefere to work with someone who have track record in this area. It is about yet another Sudoku Game, the graphics need to be of high level (see Sudoku2) http://itunes.apple.com/us/app/sudoku-2/id366247306?mt=8

If you advise me to go to a freelancing site, which one is best? how much should i plan for a high end designer?

It will be about 8 screens to design plus the game icon.

Thanks.