some of the matte pigments and a couple of metal ones are only 2.5g vs 7.5g. its not a misprint and you aren't getting ripped of. it has something to do with the ingredients, weight, etc.
and if some of your pigments aren't full, they're not all gonna be. they are measured by weight and not volume. when they ship, it all settles to the bottom, and the jar can even look only half full.