Dick, if the only service being provided is to IFRs then the cost of "C" and "E" is identical. If the controller says "clearance not available" the cost is the same as they're only providing a service to IFR. If the controller provides a clearance to a VFR because they're able to the cost is the same as they're still the same controller servicing the airspace.
Now how about you and Leadsled justify your stance that "C" is more expensive than "E". Just saying "FAA" or "USA" doesn't amount to an argument in any way or form.
You're totally out of touch with reality.