I'd like to know what a nickel, dime, and dub sack are and how many grams there are. I was told a dub is $20 and usually has 2 grams (I know prices differ by location, this is just an example where I live). I was also told an eighth is about $40 and has 3.5 grams. It seems the more you buy the less you get. Why not just buy dub sacks? Is there a half an eighth option?