but now there is no +1 coming from the warriors for this particular system, there is only the raping that the Crafters will be doing for their own profits, something that came to me just now, to ease the system why not, instead of having the crafters infuse the materia, make an NPC (it can be a mystical tree, an actually character, whatever) that infuses the materia for a FAIR price (or hell for free but this is prolly asking to much from SE).

That way you have two things happening:
1) Crafters are double dipping anymore
2) Gil is getting removed from the system, something that need to happen to promote a healthy market balance