You could show different prices for logged in members but you would have to create two different collections and two different stores.
One with products and regular prices and another with the products and the member prices. You can then display the member versions of the products on members only pages.
Thank you very much Dara. One more question. How can I offer different delivery times for different objects. For instance product A takes 1-2 days to ship and product B take 3-4 days