retipping for Grado The Reference high output cartridge

I don't know why Grado only offers new purchase as an option on their most expensive cartridges.
I don't think the lesser versions that you mentioned would be in the same class as The Reference.  I've owned so many of them; the real basic ones, the gold, even the Sonata is not as good.

Grado just like any good manufacturer do not retip, they get your old and give you new cartridge with special discount (only if you send your old cart to them). 

Grado XTZ is Signature Model, top of the line cartridge from Joseph Grado himself, it's his best, but discontinued model (styli still available). Can be different from you model, but it's a killer cartridge (I've mentioned that only because it's the best Grado with replaceable stylus that I know and own, the stylus alone is about $500). 

Thanks to everyone for the input.  Very helpful.

what the bejesus is 'diamond twin tip' ???