The ability to recover merchant fees on top of entry fees is an optional feature in Award Force. The surcharge recovery % set for merchant fees is up to you as this depends on your costs, your payment gateway, and the terms of your agreement with them.
Merchant fees are different from bank fees - GST is charged on credit card fees and therefore a GST credit can be claimed on these expenses. This is why on checkout, the GST amount is added after the merchant fees have been calculated. We have carefully researched and checked this calculation.