I would actually like to have dual listings for visitors where a product is available for purchase to a paid member but a person who is not a paid member or not logged in would not see the add to cart button. I have figured out that I can create a item with stock quantity of zero and then use css to hide the out of stock graphic. I can then put such catalog/directory items into their own category separate from purchasable versions for paid members.
I will be using Membership for access control. Is there a way to use Membership to control who see which category using positive and negative rules? It looks like no, as Membership integration with Marketpress doesn't appear to allow rules for selected categories.
Any idea how this could be done? What would it take to get make that possible, such as with a hack or custom coding?