I haven't added it up, but I bet I've got close to 300K in my plane, and it's worth maybe 250. On top of that, I fly 160ish hours/year, so fuel alone runs around 12K. With the annual, other MX, reserves, etc I'm probably out of pocket 20-30K. I *think* I could probably do my 3-4 big trips per year by PC12 for that kind of money.
Far more if I wanted to do airline first class, but the on-plane experience is not the part I hate about airline flying.
Obviously the fun lunch flights, POA fly-ins type of stuff would be out, and I wouldn't need the proficiency/currency/exercise the engine flights. Also, the spur of the moment and the hops from one small airport to another on long trips would no longer be feasible. Arguably there is some value in the hours I put in my logbook. At least some of the money I put into the airplane I'll get back when I sell. My recent engine overhaul for example probably increased the value of the plane by more than what I spent on it.
Sitting in the back wouldn't be nearly as much fun though. I love making the plan and executing it. As with most of us, the challenge and feeling of accomplishment is most of the reason we fly. I get far more enjoyment out of my plane than just the places it takes me. I agree with you though that the travel opportunities it creates are well beyond what I could afford to buy otherwise.