Hingey
I don't know where you got the Exeter landing fees from, but you must be working from an old 'menu'
It is a lot more than £7.50, and you also have to watch out for the massive late-landing charge (esp on a Saturday when the airfield 'shuts' to GA an hour earlier than normal)
Add to that, Exeter has not signed up to the Strasser agreement for weather diversions, and it is certainly not a friendly place for GA