At one airfield in which I was involved with the running of, we scrapped landings fees, lowered the cost of the fuel and bought a good coffee machine. We made more money! Aircraft owners are strange economists. If they can see a way of saving a couple of quid - they will do, depite having spent many times more on getting to your airfield. They are also natural moaners. "Do you know what I paid at Kemble last week!" overheard in the club bar will put off any prospective customers.
PS. You should have seen what we charged for the coffee!