This will have 4 categories (excluding the difference between admin shops).
Buy: Items can be bought with Gold notes (but the price is a number not an item, player's open the shop formspec by using either a Debit or Credit Card where the purchase will use either card, but the shop can be opened if the player opened it by using anything but a card then all available gold notes within the players inventory is used).
Sell: Items can be sold for Gold notes (the price is a number not an item, player's can open the shop's formspec using anything, if they use a Debit or Credit Card the purchase goes to the ATM account balance, regardless of credit owed, if not opened with a card the shop will check if it can place gold notes into the players inventory, if so it will place gold notes, else the purchase goes to the ATM account balance)
Trade: Items can be traded for other items (the price is a item, player's can open the shop using anything, if they used a Debit or Credit Card an additional check for any price using Gold notes is issued, in which those items can be bought or sold as if the player's inventory has gold notes but is transacted by the ATM account, if using a Credit card for buying the amount is placed onto the ATM account's credit owed, but if it was a sell the amount is added to the accounts balance not credit owed, if the player opened the shop's formspec with anything but a card then the price item is exactly what item it is, that is if it's gold notes the player must have the gold notes to proceed, and or inventory space)
All shops can be placed on top of a chest (assuming a locked chest) to allow for extra stock. (excluding admin shops, which have no stock limit and never run out of notes to give players from sell shops)
Todo: