[Marshall V. Daut]

There is "rebuilt" and there is "rebuilt". One man's idea of a "rebuilt" starter is to put in new brushes and paint the case black. The next level might be to clean and sand the armature plates and the commutator, and perhaps reseal the windings with Glyptal. Then installing a "rebuilt" armature and field coils would put the starter up to the next level, whatever a "rebuilt" armature means. Finally, the best "rebuilt" would be with a new armature, field coils and brushes. Add up the cost those three items alone (assuming the terminal post and wires are o.k.) and see how much a TRULY rebuilt starter might cost. And then add labor to that. It adds up quickly if a quality rebuild is desired.
If I were interested in buying your starter, I'd want to know what was done to it: freshened up or truly rebuilt? There would be a significant difference in dollars in the selling price. Ask the shop that rebuilt your starter just exactly what was done to it and what parts were installed. That will give you a better idea of its true value so that you can ask a fair price that will satisfy you and the buyer.
Marshall