ShelfItemAmountOvercharge

The BuyItemAmountOvercharge is what the shelf will say when selecting an item and there's a overcharge (negative discount) applied to the shelf's stock.

ShelfItemAmountOvercharge: ["There's an overcharge {1} on {2}, how many would you like?"]

{1} = "of" + percentage of overcharge (optional) (for ex. 12%)

{2} = Chosen Item's name (plural) (for ex. Potions)

ShelfItemAmountOvercharge 1

Just like with BuyItemAmountDiscount, the {1} is optional so you can also just put:

ShelfItemAmountOvercharge: ["There's an overcharge on {2}, how many would you like?"]

ShelfItemAmountOvercharge 2