I don't do much starter work, but I do rebuild old generators. Most people have no idea how time consuming it can be. I often spend 10 hours or more on a generator. Tear down, cleaning, inspection, making new wiring, new insulators. If not replaced, rewiring and rewrapping field coils. Testing the armature for open, shorts and grounds. Truing the commutator. Undercutting the mica, resealing the windings, new bearings on and on. I do it because I enjoy the challenge, not to make money. Being thorough is not profitable. I build them to help out local guys and occasionally sell one.
Drifted off topic - sorry. What's your starter worth - as Marshall said, it all depends on what was done to it.
Just for show n tell. Here is a flathead V8 generator I finished last week. It was pretty rough to start.