If you travel with a loco then airport spending is never going to be huge and the customer base for NOC is largely Irish and if you are flying out you will spend lots at the returning airport.
You do have to consider the ADF charged and how only regular passengers will only know about it as Ryaniar don't display it. people who planned to pick up some bits will be put right off as a family of 4 will be down 30-40 euro depending on age even after paying for flights by the time they reach the check in desk.