is this even allowed to be sold here ?
Hard to say. Crypting by itself isn't a crime, but it's obvious that people intend to use it to remove AV detections/flags of mallware and trojans.
imho this shouldn't be alloved here, nothing good can come of it, and even if the crypter is indeed crypting ,there is always a chance that output file
is getting binded with pre-arranged mallware from owner, both to infect user and to steal other users infected via botkill.
Just be cautious people, use your brain.