I've notice that I can't buy items on a vendor without the correct cogs in my inventory, so I proposed an idea where instead of carrying a lot of different types of cogs in the inventory we can just purchase items in the vendor using a bank card either in the curios slot or inventory, it also works if the bank card is only bounded to a player or multiple player in a single card.
(edit note)
if a player has multiple card it only takes money in the bank card that is in the curios slot or the very left side of the hotbar