Somewhat off topic here, but this story just made the news in Boston: http://www.thebostonchannel.com/news/24496326/detail.html
A mailman arrested for delivering OxyContin to "clients" on his route. I include it only to show that there's a lot of "delivery" type stuff going on that doesn't involve being a trusted part of a major gang. It can be just a couple of people going freelance.
That's more realistic in this case, too.
Most of the Oxy dealing IS done by freelancers, and it's more profitable for them. "Make money fast..." and all of that.