Buying Premium/Gold plans selling them to players and saving up that gil will give you not only the edge to buy a House (would need to be a FC house for the airship)
But it will give you a huge boost over other players in the crafting end game as well. Letting you buy Artisan gear and Materia for this gear.
And since the airship system will require crafting, you could take advantage of this system to produce an airship faster.
Although Building an airship is a group effort, so you would need to gear up people in your FC as well
