I don't know many dealers that shot 4 Oz at a time anyway, it's usually a 9 bar or half of that which would be 4 and a half Oz, not 4 and not for 520 pounds. If you sold all 4 Oz for 130 then you get 520 so that is such a shit deal it's crazy, no let off on a huge bit. This person is a piece of shit, i am 99% sure of it. Take his money, fucking tax him, light up a candle and hot wax him.