It is illegal, but it doesn't stop people from doing it. In fact, if you don't have any sort of test results for your peptides people will absolutely avoid buying your wares until you have them. Purity and mg/ml are the 2 basic test results that any shop worth their stuff will have.
After nearly getting hosed in a group buy (I did get refunded, but that is far from a guarantee) because of a product mismatch, I decided to just pay for nexaph. Love him or hate him, his popularity relies on his reputation and he has been more careful than most suppliers to cultivate it with more extensive testing and quality control.
<Insert that "one of us, one of us..." GIF here>
I know a bunch of people with multi-year stockpiles. I've got ~5 years of reta and ~6 years of tirz. This is too much, of course, but I determined a while back that under no circumstances do I ever intend to find myself unable to source it. My life is immeasurably better after losing 110 pounds.