If you want to get into the "underground" world, and not gehtfuct, then it's probably wise to strike up a relationship with a dealer that's a little smarter about what he's doing, and keep him, don't float around to dealer after dealer.
Sure, you geht a bad sack every once in a while, but shitty sack, after shitty sack means it's time for a change.
If you become a regular with someone who gives you a decent bag, then chances are if you stick with him/her you're going to continue to geht decent bags.
And it's a bit safer. Better than walking the streets downtown looking for someone who's slingin.