Can I add a fee to a specific gateway?

Hi, is there a way to add a fee specific to a gateway?  In my case, off-line would have no fee but paypal would have a transaction fee. Alternately, can the off-line gateway have an automatic "discount"?

As a non-profit, I would like the user to pay the cost of a credit card transaction instead of our society paying it.

Thanks, Kerry.

Yup, that's doable. Both are in fact. It however requires you to use radio select for payment methods otherwise payment method is effectively disconnected from the basket process until selection.

So first navigate to CBSubs > Settings > Display > Baskets and set "Choose payment method" to "Choose payment method by showing a radio-selected list of payment methods"

Now all you need is CBSubs Promotions. Negative promotions increase price while positive promotions decrease price. The below is how you'd accomplish this.

Basic
Promotion Type: Applies to all purchases
Conditions
Date A, Field A or Value A: Constant Value or String (CB substitutions can be used)
Value A: [PAYMENT_GATEWAY_ID]
Date B, Field B or Value B: Constant Value or String (CB substitutions can be used)
Value B: GATEWAY_ID_HERE
Condition 1 (> for Dates): A = B (Value A is equal to Value B )

Replace GATEWAY_ID_HERE with the ID of the gateway you want this discount or price increase to apply to. You can find the id in CBSubs > Gateways to the far right under the ID column.

Now just configure the rest of the promotion however you like. The Name will show in the basket so for example you can name the offline payment gateway promotion to "Cash Discount" then give for example a 10% discount.

OK, that works perfectly, but I can't find where to change the text of the payment options. Below "Choose your payment method:" both options show up as plainly "Credit Card". The button shows up once you click one of the options but the user needs to guess which one is etransfer (off-line) vs credit card (paypal in this case).  Where can I set the text? 
I tried to upload a screenshot but upload is failing for some reason.

Thanks, Kerry.

Edit your payment gateways and you should see new parameters available for you to customize that text per-gateway.