Referring back to this post https://premium.wpmudev.org/forums/topic/few-questions-about-marketpress#post-211591
Kimberly said that a way of offering discounted products to members was to create a 'member shop' which only members can access. I can see how you'd achieve this by denying access via URL groups or product categories.
However when you create a product in MarketPress the direct link to the product will always be accessible to non-members (unless you protect each product's URL directly)
So how do you suggest setting up a members shop which non-members can't access products even if they know the product URLs?