No, that's not how it works, ohshea. Atleast not in NJ.
Over here in NJ this is how the open air market works.
The 'D Boys' have individual sets all around the city ran by multiple 'D boys'
You drive to the set, park up, hop out the car, and approach the 'D boys' and tell them how many dope you want.
They then retrieve the dope, come back to you, you hand over the money & they give you the dope..
NEVER give them money if they don't have the dope. NONE of the dealers over here ask for the money first.
That's how you get beat. The only time I'll hand over the money first, is if there are multiple people out on the set (Dealer, Look outs, etc) & If I personally know the dealer, or most of the people on the set.