When the starter in my BMW Touring took a dump, I priced repairing it vs. replacing it. New solenoid, brushes, bearings, and sprag clutch came out $13 more expensive than just buying a Bosch reman, and that was before the core fee refund. Unless you have the parts sitting around, you have a way to get parts at wholesale costs, or you "know a guy" you can get them from cheap, a genuine Bosch rebuild will very likely be the same cost or even cheaper. Considering the PITA factor of doing a starter motor (BMW M60 makes the OM617 seem elementary), it's a no-brainer which avenue I chose (and for less money).