"I guess that my view is that a rebuild should provide a cartridge that is better than new. The same as new is just not good enough.
Cartridge improvement is offered by Soundsmith and probably some other companies. They can rebuild a cartridge and make significant improvement in cantilever and stylus and performance. The turnaround leaves something to be desired, but the results are tremendous."
The 'Frog' retails for $2500+. I bought it new, wore it out and had it re-built by the same person (A.J. Van Den Hul) that originally built the cartridge. Cost inluding shipping? $293. My cost for the life of 2 very good carts almost cut in half. I don't know if A.J. does all the non-VDH re-builds. That would be a question for Dale at Eugene Hi-Fi (and I do concur - top-rate guy).
I don't have experience with Soundsmith. I do with VDH. For a high-end cart, I think it would be next to impossible to get better service than VDH, I suspect it would be difficult to provide the same quality of service as VDH. For an originally lesser expensive cart, there may be better alternatives. I can only speak of my experience.
Don