3. The method of claim 2 , wherein the first pricing sub-model is set at a first instance and the second pricing model is set at the second instance that is substantially distinct from the first instance; and wherein the first and second pricing sub-models are set through an administrator interface.
3. The method of claim 2 , wherein the first pricing sub-model is set at a first instance and the second pricing model is set at the second instance that is substantially distinct from the first instance; and wherein the first and second pricing sub-models are set through an administrator interface. 4. The method of claim 3 , wherein a billable item of the second pricing sub-model applies to a billable item of the group of billable items of the first pricing sub-model.