When you would go to the store,it would have the ranks you can buy,but maybe you could add where the player pays for a certain entity to be spawned in their base (or wherever) for example the player could buy a vending machine for their base etc etc (this could also be added into the ingame shop)
I believe that is beyond the capabilities of the game at the moment. Definitely beyond Rocketmod which has been having a bad go of things since Nelson and the Rocketmod developers moved the default folder location on the server.
that would be very problematic because then people will build their base out of vending machines so absolutely NOONE will be able to get in, and plus there are already way to much wooden blocks everywhere in the world to lag, and u want to add vending machines, houses, ect? that's a little bit to overboard