Perhaps worth remembering that an airfield is not a public road and so brings all sorts of additional liabilities not covered by 'ordinary' motor insurance. By itself this can be a significant extra cost if only because you are now in the territory well out of the mainstream market.
Yes I loved the old Cranfield events, Wroughton was not nice and Kemble was OK. Sywell I can take or leave. It is good to see there still is a rally but it really should not represent a threat to the organisation. But equally the LAA have curtailed a number of things which were a real 'feed stock' on the basis of risk aversion- anyone remember Young Eagles?