As someone often paid to think like a criminal ( in order to stop criminals ), these look like a prime opportunity for a violent cartel to both stock up on ammo and launder money.
Come to think of it, that may be a meta-joke I missed in Borderlands.
The photo recognition ought to put a bit of a damper on it, but I feel like a motivated “investor” could find work-arounds (or just unwitting “mules”).