Which cantilever to choose for re-tip

Shelter makes great sounding cartridges; I just wish they had a rebuild, retip, or at least an exchange service - but I've never heard any examples of such a thing? 

What's a shame is that a brand new 501 Mk III costs only like $1000 or so from Japan, right? The $450 boron retip would get you back a Mk II at best, and that's close to the 50% cost of a newer Mk III that you'd expect to get back from a rebuild service (if Shelter had one price-structured like Ortofon and Koetsu). And of course the ruby cantilever will definitely change the sound, maybe not for the better. I don't like either of those options. I'd probably try to see if another retipper can keep boron for less money, or I'd get what I can for the 501 as-is by hocking it, and then buy a brand new Mk III from Japan.

Stick with the Boron.

Ok. Seems boron is the way to go on the Shelter. More than half what I paid for the cartridge but still seems worth it if it sounds great when repaired.
I decided to have them evaluate the Lyra. The stylus looks fine but has turned sideways. The cantilever is loose. I hope they can glue it.

FWIW, I chose boron for my Benz Ebony LO, which is what it came with, and I'm very pleased. Sounds like stock, which is what I wanted.

I can't swear to this, but I do believe the Mk3 was at most only a few hundred bucks more than the Mk2 (not double the price of a Mk2), last spring when I was in Tokyo.  It may even have been the same price.  I eventually bought a Mk2 Mono.