I'd try changing the bushing first. If you replace the starter, you need to install a new bushing anyway. They usually run about a buck from a parts vendor at a VW show . . . they are probably 3 or 4 bucks at a regular parts store . . . if they carry them. Still, it's cheaper than a starter . . . and again, you'll need to replace it when you install your new starter. I've fixed a lot of dragging starters with a new bushing.
If you do replace the starter, listen to David. Use Bosch. I finally listened to him and replaced my off-brand voltage regulator with a solid state Bosch unit and all kinds of electrical problems magically went away. Before the Bosch regulator, electrical parts (starters, generators, BATTERIES (lots of batteries), bulbs, flashers, etc., etc., etc.) were going bad right and left.
By the way, I got the regulator from Al Johnson. They were the only place in the area that had it in stock and they were as cheap as anyone who could order it . . . cheaper than most. It's nice to know there is still at least one VW Dealership that remembers that Volkswagen used to make a little funny looking rear-engined air-cooled car. :wink: