Most of the activity in this field is grey at best and at worst illegal. You should steer clear altogether.

Especially with "bulk suppliers" who are actively seeking out 1000's of dollars worth of cards from a "long-term seller" at high discounts (I'm talking >50%), it is pretty much guaranteed that they are not in the legit business.

Watch out for these people on paxful too. If you use a highly discounted GC that proves to be stolen/hacked/carded and you use your address on the order, there is a real risk you'll have law enforcement knocking on your door. Check out some purse.io stories on reddit if you don't believe me.