don't listen to this spoon guy, take it from an experienced crafter as myself instead, I managed to get to max firearms grinding for like < 2 weeks

. Craft whatever you can that is the highest level and make sure that you don't overprice your items too much. I used to take ~1k profit on some guns and then just reinvest the money in more materials to craft more guns. If you need more money though, crafting ammo is solid since youcan sell pistol ammo for 1k easily so you get 200$ profit from every box.