Gymno monvilei is somewhat common, even here. Bear in mind, when it comes to availability, i operate on hard mode
cacti guide also says "common"
https://www.cactiguide.com/cac...
I used to own one(mistaking for a ferocactus). Thus i am familiar with spines and shape.
Now...i only own its slightly rare variety, horridispinum.I nearly bought a regular one, but it was mislabeled as echinocactus grusonii , and slightly more expensive...
Considering how most cactus wholesale is fairly similar, its a safe assumption that it is this one, and not another gymnocalycium..