ok, a 30 sack is just a bag that costs $30. Most prices (around the west coast, USA) are 20 dollars a gram, so instead of saying 1.5 grams, we say a 30 bag. If I was gonna spend 50 bucks, I'd say a 50 sack. And an ounce typically runs $125-$150. A dub is a 20 sack (or a gram), a 1/16, 1/8, 1/4, 1/2, etc.. those all refer to percentages of an ouce. Like 1/8 of an oz.?

I hope this clears things up a bit for you.