Is there an additional charge Feature for the Payment Method Fees at my store?

Yes .. There is an application called Payment Method Fees ...This application is very useful especially at payment method (cash on delivery)

Add custom fees to the order based on selected payment methods, and define order amount ranges to show or hide specific payment methods.

The following features are available in the app:

• Specify custom fixed fee or percentage fee for each payment method.
• Define the order amount range to show or hide each payment method.
• Define an order amount range to apply the custom fee on each payment method.
• Specify a custom name for the fee to be displayed on order and checkout page.

You can get the application through the going from  control panel into applications and services ...  It is also available for free on the Enterprise package . 

The cost of the application on the other packages is  39 $

On the next link you can learn more about the prices of plans with the applications attached with each one

https://www.expandcart.com/en/online-stores-pricing/