and others lower - servicing by enthusiasts.
Err that is rather disingenious, most are ex services and are approved or licenced, far from the "enthusiasts" you quote.
I would ask a company that maintains them etc for an idea of the costs, one based at RAF St Athans is as an example, see
http://www.horizonaircraft.co.uk/
Horizon Aircraft Services Ltd (HAS) currently support the operation of many airworthy aircraft on behalf of their owners, which includes Hawker Hunters, Percival Jet Provost / Strikemaster, Yak-50 / 52 and Aero L-29’s.
We are also able to undertake all aspects of servicing and support on all of these types, as well as many others.