"Rare and endangered" snakes are covered by various bits of legislation including CITES.
Importing them legally, there would be very little likelihood of them ending up as pets. They'd be prohibitively expensive because of the associated paperwork and admin required. They'd most likely end up with specialists, in breeding programmes - which is a good thing if they're rare and endangered.
Importing them illegally would bring pretty much the same problem. The risks involved would make them command a hefty price tag, making the potential market for them extremely limited. Basically, they would go to a handful of immoral collectors (as opposed to pet owners) who don't give a hoot about the provenance or cost of an animal if they just HAVE to own it. I can't accept that there are many of this sort of person.
Being charitable, it seems that the people running the Facebook group have been badly misinformed on the subject. There simply isn't the kind of mass market for rare and endangered reptiles that they're assuming.
