Wow.
You got some fucked up prices.
In Canada,
10$ = 1 gram
25-45$ = Half quarter ounce = 4 - 4.5 grams
56 - 60$ = quarter ounce = 7 -8 grams
90 - 120$ = half o = 12 - 14 grams
200$ = ounce = 23 - 25 grams.
Its that simple
It depends on how good the bud is.
Most of the time you dont get a proper count if your grabbing off people you dont know very well.