SBK-07: Superbike World Championship for the PSP is just £17.89 delivered @ Sendit.com! Cheapest i see elswhere is £23.99.
Details: SBK is the Official game of the Superbike World Championship. All the real elements are in the game, and you can go into as much detail as you want in the way you make your gameplay.
Nothing has ever come closer to the real experience.