It's impossible for us to tell you what amount yo should be getting because we all live (for the most part) in different parts of the country, smoke different bud, and have different types of dealers. If you live in a city, expect to pay more than someone living in the boonies or in some suburban area. The more you buy grams, 8ths, 1/4s, zips etc. tyhe better you begin the reconize what it looks like Eventually if you keep smoking you should be able to find a dealer you can trust (try not to get weed in school btw, not worth getting caught) and you won't have to worry about exact weights anyway.