MC cartridges

I find that Elusive Disc has a nice selection with very competitive pricing.

https://elusivedisc.com/turntable-cartridge/

Official US distributors of some great phono cartridges are: 

1) Mehran at SoraSound (the best dealer I ever dealt with, you will be surprised) 

2) Robyn Wyatt at Robyatt Audio

Do any of these companies keep these cartridges in-stock? I'd think they just order from the respective importer. I'd buy from who gives best discount, I've found some dealers that will offer upto a 20% off mrsp especially if bought from them in past. 

Not in the US, but seller kron here on Audiogon has a number of Dynavectors for sale.  Grey market, so no warranty.

Here ya go!
https://www.audioadvice.com/turntables/phono-cartridges