It makes me wonder, thinking of this in the context of a D&D fantasy world. If it's SO expensive and difficult to make a suit of full plate armor, but apparently not very difficult at all to enchant some lesser armor, which will then be just as protective as the full plate, why would anyone ever make full plate anymore? If +1 Splint Mail is cheaper and easier to produce than Full Plate, why ever make Full Plate? Why ever wear Full Plate?
