I don't think any GA airport can survive in a good condition (hard runway and taxiways, no potholes, working lights, etc) and the mandatory ATC without some commercial property rental income. Or a subsidy, which is not going to happen in the UK.
Stuff like an ILS is a big extra cost which can be avoided with a GPS/LPV approach. The problem is that almost nobody (apart from a few pilot forum posters) has the equipment installed and approved to fly LPV and this won't change for many years.
The next step down is to not have ATC and that saves a large bundle of money (the silly useless airport opening hours we have are mostly caused directly by payroll costs) but under the UK rules you then lose the IAPs, which kills off a lot of utility (i.e. income).