1. A method for evaluating usage in a communications platform comprising: defining a hierarchical structure of pricing models for a set of billable items in the communication platform which comprises: setting a root pricing model for the set of billable items within the communications platform, 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 communication platform; receiving a communication pricing query; mapping the communication pricing query to a billable item; resolving a price of a billable item within a set of pricing models which comprises: identifying a first pricing model that most specifically applies to the billable item, calculating a price at least partially from the first pricing model; and returning the price of the billable item in a response to the communication pricing query.