My understanding of Epic's approach, to some extent, is that they know approximately how much it will cost to support an organization. When we were going live they had reservations due to our size at the time; if we were not big enough they did not want us as a client since the cost of support would be greater than what we honestly afford.

I really like how they have structured the support concerning Forums, UGM and Good Maintenance; for an enterprise software company it is the best approach I've seen.