Surcharge for payments made by card through Stripe

As card transaction fee's continue to take a large chunk of small business revenue, it would be great to have the option to add a surcharge to Cin7 Core quotes/invoices when a customer decides to pay by card (for us mainly through the Stripe payment integration).

For example, we pay 3.2% plus $0.30 on each transaction from a foreign card (majority of our customers). We would like to have the option to oncharge this cost to our customer automatically as many retailers/companies do here in Australia.

The problem is that we also offer direct bank transfer as a payment method and so it doesn't work to simply add the above costs to each order.