The extension Discount/fee by Payment methods allows to set discount or fee based on payment type selected on checkout.

Features:
* allows to set discount or fee based on payment type selected on checkout
* allows to set amount in percents or direct value per payment type
* allows to set cap of the discount/fee
* allows to apply to specified range of total only
* allows to set message string in module's admin page with multi-language support
* allows to set categories where discount/fee is accounted

Demo: http://oc.sad.lv/23/admin/?route=extension/total/discount_by_payment
user/pass: demo/demo