<<Admittedly, my experience with the cost of rewinding motors is limited
to some larger 3-phase monsters, so my perceived baseline may be a bit
skewed. The rebuilder we use for motors charges $75/hr (plus material),
and I can't imagine rewinding an armature in less than 2 hours. Just
seems to me that you'd spend less buying a $160 rebuilt with known good
windings. "Sometimes cheaper?" What does that mean? If you've had it
done and know it IS, tell us so we're better informed. If you don't
know, well...what can I say?>>

I do know that any automotive starter can be rebuilt, and rewound by a
starter specialty shop here for $125.00 to my specifications.
And that's gives me a totally remanufactured starter.
Bushings, windings, cut / replaced commutator, brushes, solinoid ( if
required) gear drive.
Not just looked at and "rebuilt."

The stuff you buy at the "Zone" or most any  over the counter purveyor
of starter's is only rebuilt by replacing what the minority worker's
sitting at a bench all day, in a mass production rat hole see is bad.
They do not growl the armature,or turn the commutator.

What you usually get is a pair of brushes, a solenoid, maybe a new
drive, a paint job, and a new sticker on it.
They are working the odds here.
Maybe it'll work, maybe it won't.
Maybe you'll bring it back, maybe you won't.

It's a crap shoot.
Your rolling the dice.

The armature de winding / re winding is done by a machine, not by hand,
and takes all of 10 minutes, not hours.

I get heavy equipment starter's done at half the price of new, and to my
spec's.
Alternator's and generator's too.

If you find a competent starter / generator / motor rebuilder hold on to
him.
it's another dying art, and no Nintendo kids will be soon replacing
them.

 How do you know what Bosch does, or doesn't Do?
You been at the rebuilding plant and checked them out?

Just cuious.