Preferably during sale I would like for you to format the total amount of product but priced for half so there is no mistakes during the ordering process. So that would mean 1 NPP=$40 at regular cost. But when you order during sale you would put 2x NPP=$40 BOGO Instead of 1x NPP
Till items of overstock that are on sale run out. If some items sell out before others they will be removed for the sale list. And priced as regular price.