Have you thought about Motorgliders? If you have any gliding experience, the conversion is simple and you have the option of turning the engine to 'Silence' for some real flying. Probably can't quite get into the right price range for outright ownership but a single seat Fournier starts at about £8k. Costs are as for a PFA Homebuilt with a VW. My Ogar syndicate, 6 people, costs £35/Month and £18/Hr.wet. The £18 would apply no matter how many in the group.
Mike W