He should not sell an armor piece because he sells an armor piece for each class and unless he sells a forsaken armor piece for each class then it wouldn’t be fair for the other 2 classes. The best thing to do would be to sell a forsaken weapon, Cerberus+1, trinity ghoul or talon sword would be best as they don’t break the game with everyone having them, two tailed fox might even change gambit a little bit if everyone had a powerful tracking rocket launcher.