Magento Add Fee or Discount to order Totals.
In a typical order, the order totals usually comprises of Sub Total, Shipping Cost, Taxes, Discount, based on these values the total order grand total is calculated.
This module adds a new line to order Totals. You can add an additional Payment Fee which will affect the order grand total.
This extension based on Magentix Fee module (https://github.com/magentix/Fee)
Magento 1.7.x
Extension Configuration
Checkout Totals