PN,
Here is the tariff for tickets for RIAT Fairford 2016 - GBP 44.00 (Earlybird) - must be bought in advance - no tickets available at the gate.
Royal Air Force Charitable Trust Enterprises - Tickets and Upgrades
In the overall equation of the economics of RIAT Fairford, I imagine they rake in a huge amount for the marquee enclosures taken by industry for hospitality. I too cannot imagine much of a market for that at Scampton which might have a knock-on effect on the ticket price for normal punters.