Insurance could be interesting. In the US “Flying” magazine, a pilot with 4000 total time, 1000 turbine, 2500 multi, type rated B737 and Cessna 500 was quoted $37k annual premium. Maybe quite a reasonable cost relative to the other costs of ownership.
But for another pilot to fly his aircraft, Insurers wanted ATP, 5000 total, 3500 multi, 1000 pure jet, 250 make and model, school and annual recurrency.
Europe is not USA so the insurance picture will be different and a Mustang at $2.5m is not an Eclipse, but a point to ponder.