I would like to remove the "add to cart" button for guest users on my website. Instead, they should log in before being able to add an item to their shopping cart. As of now, guest users are able to add items to their shopping cart therefore being able to view the prices even though on the product page the prices are only shown to registered users.
My site is setup with three types of users, "Guests", "Registered Members" and "Author Members". "Guests" are not allowed to view the "add to cart" button.