Instead of making a new piece of armor that gets thrown out for each level why not focus on quality visual armor every 5 levels and add horizontal progression within that piece of armor. We have so much materia why not add unique slots to a cool looking level 80 gear that unlocks a special slot that requires enhancement with a materia or with a disciple of hand?

So at level 81 or 82 a unique item is required to be made or obtained (easily) in order to strengthen the armor. Perhaps when the armor is upgraded it changes slightly visually or give the visual choices to the player to select from.