Re: Economy of scale - F-35"D"?
Re: "Scale up production to bring down the unit cost - but who can buy many hundreds, if not thousands of these aircraft?"
Well not sure about complete aircraft, but cockpits plus a bit...
Taking "The F-35 full cockpit simulator at the press event had been set up in London, as part of Lockheed Martin and the Ministry of Defence's efforts to tell the Great British Public that the heart-stoppingly expensive "fifth generation" aircraft really is worth its £100m-ish price tag." I suspect there might be a market in low end simulators for games arcades, and high end at places like the Fleet Air Arm Museum at RNAS Yeovilton.