16. The method of claim 15 , wherein defining the hierarchical structure of pricing models comprises setting a root pricing model for the set of billable items within the telephony communications platform system and setting a set of pricing sub-models that sparsely over-ride at least a portion of the root pricing model for a subset of the billable items in the telephony communication platform system.
16. The method of claim 15 , wherein defining the hierarchical structure of pricing models comprises setting a root pricing model for the set of billable items within the telephony communications platform system and setting a set of pricing sub-models that sparsely over-ride at least a portion of the root pricing model for a subset of the billable items in the telephony communication platform system. 18. The method of claim 16 , wherein setting a set of pricing sub-model comprises setting at least one pricing sub-model with a fixed price.