I want to get back to this idea of the actual cost. To mirror Dan's suggestion, imagine I'm an administrator and I have people under me who are offering a service. What do you actually include in the cost of that service? You could move up the chain of hierarchy, and you could start including someone's salary here, here, and here because this person spent 1% of their time doing that service, this person spent.... You know, the hierarchical thing. You add it all up, but as you move farther and farther up, you could increase the costs, perhaps exponentially.
What's the mechanism you have to prevent any abuses?