@jperry cartridge re-tipping is a good business, but most people don’t really understand what’s going on, so they trust to the retipper. The retipper does not have to explain everything in technical details (it’s too complicated), except some simple things. If a cartridge is back to the owner in good working condition the owner is happy. But the devil is in details.
None of the retipper is forcing a customer to proceed, the customers comes by their own, but a few people really understand the trade-off between original parts (sometimes unique parts made expecially for the cartridge designer) and different parts coming from the retippers (not bad, but different). J.Carr explained everything as a cartridge designer. There is a calculation of many parameters for a cartridge designer to use certain type of cantilever, stylus, suspension, coil material etc. The retipper has no idea about it.
In my opinion if you can’t service your MC cartridge with the original manufacturer then do not buy it or simply be aware of the expiration date of that original product.
I believe that the average cheap cartridges can be upgraded by retipper with better parts such as stylus/cantilever, but very special cartridges can not be upgraded by retipper if the retipper is not the original manufacturer of the cartridge.
The MM/MI cartridges are much better because the stylus can be replaced with a brand new original by user himself. Even very rare MM cartridges that cost over thousand dollars can be updated with new original styli. We can be sure that we’re listening to the original sound of the certain cartridge.