Idk on most stuff, but I do know rebuilding them is at least half of what a new one costs. Depends on what it's for, and if they just bring in the part, or we take it off. I did 2 starters today, and just happened to be up front when they came in. One was $45, the other $135. Cheaper one only needed a solenoid, other needed that, armature, and brushes. The guy who paid 135 asked what a new one costs, they looked it up, and it was $295. I did a couple of altenators, and they weren't much, except the one I had to take off and put back on the truck. He paid a little more for labor.