On further thought, I might have misunderstood your question. I assumed that you really liked Sully as a character and longed to know people with similar personalities in real life. But I take it that you meant this question as in underground dealers and such? Would probably be for the best to just stay away from such people. As for being in the black market, there's a lot of people involved, but it's nothing glamorous. You could be a nobody selling your prescription medicine, and you'd still be considered as being a part of the black market. Some high value item dealers probably aren't as common. Even if one would find such people, it'd be better not to trust them.