In the Billing Module, the USPTO fees have already been imported and are maintained by clicking the "Load USPTO Fees" button in the Billing Item Templates section.
It would be amazing if you could also include European Patent and Trademark fee schedules, Madrid Trademark fee schedules (although that might be moot given the calculator they employ... or maybe link to the calculator from AppColl, add the variables, and then import the final results???), PCT fee schedules, and then maybe other countries over time, depending on volume or demand?