Concealed costs for guests: You can shroud costs for not approved (not logged) clients. Just enrolled clients will have the option to see items prices.
"Add to truck" button is covered up: Only enlisted clients will have the option to make orders. "Add to truck" catch will be covered up for not logged clients (visitors).
Message for not logged clients: You can design custom directive for not logged clients. This message is shown rather than cost and "Add to truck" button for every item.