Leveling crafting wasn't supposed to be easy, as it's the only way to create money in the economy. If everyone could do it, then no one would buy from each other. Yes, turning in HQ does give you extra bonuses. But Trade craft leves are potentially unlimited. When you have a leve that requires multiple items, if you turn in all HQ materials, then (in addition to the large bonus) you can redo the leve at no allowance cost. Remember, that it's intentionally difficult, otherwise we would have an even larger number of gil farmers.