1. A method of auditing a transaction, the method comprising: receiving, at a processor, data characterizing the transaction, the data including a first price for a travel service to be provided by a service provider; determining, by the processor, a second price for the travel service based on a pricing rule of the service provider; determining, by the processor, if the first price matches the second price; in response to the first price matching the second price, allowing, by the processor, the transaction; in response to the first price not matching the second price, determining, by the processor, at least one source of the discrepancy; determining, by the processor, at least one weighted discrepancy parameter for the at least one source of the discrepancy; determining, by the processor, at least one action parameter based on the at least one source of the discrepancy, the at least one weighted discrepancy parameter, and a set of transactions that occurred prior to the transaction; and determining, by the processor, an action based on the action parameter.