As a User who charges a processing fee (or similar) on top of the final price for an itinerary I would like Tourwriter to calculate this $ value so I can automate the work and not make mistakes.

As an example I charge a 2% credit card processing fee. If I could add a Product at some stage that would 'know' to add 2% to the Final price and display this on any Pricing/Invoicing report this would be useful.