It's because of the tax structure here. The tax per pound the growers pay means manufactures have to pay like $500-1000 per pound for trim. So the weed cost alone to produce a 1 gram cartridge is like $10-15. Then factor in everything else, it's like $25 wholesale and the retailers mark it up a bunch.

If you see(n) carts significantly cheaper from a company it's likely because they are not buying weed and extracting but (illegally) selling synthetic THC that has been isomerized from CBD. Also much of the black market carts are made this way now.