Discussion thread for my new extension. If you have any issues you can post the details here.
Bag Charge Extension
Do I get a credit 
of course!
Once I get it on the market.
wakey18 
only joking. Can’t wait to see it.
8 days later
- Edited
It’s on the market for anyone that needs it. Click Here
a month later
“I have made it possible to specify the amount to charge incase you are not using single use bags and want to charge customers anyway.”
I think you meant “in case you are using single-use bags”
In fact instead using this extension I have just set the bag charge as a payment fee for all payment methods and changed translation for payment fee to bag charge. It’s working perfectly for me.