Implement something that could be fun -> proceeds to put unnecessary materia as main rewards and 95% chance to just pull them. If you are lucky into 5% then you get useless glamour gear that costs 50 gil at marketboard.

How many of you did deep dungeons and you wonder "should I get this hoard from higher levels and risk dying?". You get it, you waste time only to realize that from those 3-4 gold / plat ultra rare hoards you get 3-4 materia lol.