dude, what the fuck are you talking about? Unless, your dealer is like the heroin dealer off of pulp fiction or the heroin dealers who sell to the movie stars or something, I really doubt that everytime you go to buy some dope your man has 4 different grades of it. I live in LA, and know many, many people who cop dope out in LA, have talked to homeless people who have been copping in LA for more than a decade, and everyone says all the dope is sold on the streets, and never have I once heard someone talk about how the dealer had 4 different grades. Its either black tar or brown powder, and very occasionally white powder from the columbians. I highly doubt that when you go to cop dope, your dealer is like "so would you like the pure shit or the totally cut shit or the stuff in between?". I think your full of bullshit man.