Why? For the adorable "Tony Tony Chopper Multi Pouch" that can be seen in the photo below.
Granted, the game itself, a PSP RPG based on the One Piece series, looks pretty nice, too, but not as nice as nice as the aforementioned pouch.
Considering the whole she-bang is going for just under $140 at Play-Asia, though, I wouldn't count on me picking it up anytime soon.
Note: All of the above is coming from someone who knows next to nothing about One Piece and even less about Tony Tony Chopper.