Depends on what is wrong with it Tsar
If its an isue of a couple of sticky buttons, sure repair it by taking it apart and cleaning it out, cleanign the button contacts with solvent etc as an example.
If its misfiring or repeating one action key, then it might not be a simple issue, it might be an issue with the PC Board, in that case, replacement controllers go for aorund 499 if you are buying the one with the PC adapter