Unless you're feeling rich I'd definately look at putting a sleeve in the cases before buying new ones if the bearings are fretting/loose on the outside. If they're fretting on the inside another option is having the journal ground down, hard chrome plated and reground. I recently had this done to my KTM sx200 because new ktm parts are such a rip off (or in New Zealand at least). cost was equivalent to about $125-150 USD to have it done to one side of crank.