Come on guys, help him out, he's new.
These are averages, for good-decent weed.
Dime ~ 1 gram, $10
Dub ~ 1.7g, $20, 2g, $25
Eighth ~ 4g, $40
You can figure the rest out, it's fairly linear until you get into ounces, but I doubt you'll be buying that much if you're just starting out.
Obviously people on here will say they get better deals, and they probably do, but I'd say this is pretty accurate overall.