subracts the item from inventory

gistfile1.txt

for i = 1, self.sellAmount do
    playerItem, pageIndex, slotIndex = self.player.inventory:search(item)
    if self.player.inventory.pages[pageIndex][slotIndex].quantity > 1 then
        playerItem.quantity = playerItem.quantity - 1
    elseif self.player.inventory.pages[pageIndex][slotIndex].quantity == 1 then
        self.player.inventory:removeItem(slotIndex, pageIndex)
    end
end

Assumes sell amount is correct