Not bad but it could be tough to implement.
I don't think it'd be too much harder to implement than what's already in the NPC. o:
I thought the OP said that only guilds that own a land can buy this. If it's in every base, then it should be easy.
unless all pots are added to be obtainable with elixir i am against this idea cause it would give unfair advantage being able to make channelling pots for example