My website will restrict access to buddy press groups by subscriptions. I would like shopping functionality to be able to offer discounts for signing up for more than one subscription. Also I want to add a transaction fee to a subscription purchase so i want people to be able to purchase multiple subscriptions at time so they will only have to pay one transaction fee. Will market pass work with the membership plugin to do this since i am not offering physical products. If not what can i do to get this kind of functionality?