I have a situation where I need to implement that when a customer orders a ticket for the event, upon selecting the payment methods, where paying with Paypal or credit card will allocate another 5.5 CHF to the bill. (e.g. Order is 30 CHF, when Paypal or credit card payment method is selected, order will be 35.5 CHF)
This is not a feature of Event Espresso where it can add additional amounts to the transaction on-the-fly based on the selection of a payment method. Some have attempted this and found there was a challenge with updating the amount each time a different payment method was selected.
What you can do is make use of the third party “Price Modifier Add-on for EE4” which allows for adding a question to the reg. form e.g.