ZAZ, I share your concern but as others have noted the costs you're encountering are actually pretty reasonable. You beat me on nearly all counts, despite having my aircraft hangared outside the capital city and maintained by a country LAME.
I'm still working professionally and while I enjoy flying lots of GA aircraft, I could see that the ability to fund my private flying in retirement was likely to be an issue. More, rather than less, cost certainty is important to me so I passed on lots of the "well-used" GA aircraft hanging around the market and bought a second-hand LSA with 500TT. (Not being quite able to cut the thread, I bought a fully certified version). It's a fun thing for beetling around the patch at the weekend - nothing too unusual these days about 105 kt at 15 lph of premium mogas, and 5-6 hrs endurance. One day the aircraft and I will end up in RAA but, for the moment, I'm happy enough in the GA world and enjoy renting a 182, Bonanza etc for the longer trips.
Maintenance will never be a bargain if it's done properly but, with an all-metal aircraft designed pretty much out of the Aircraft Spruce catalogue, the parts costs are considerably less than for other aircraft I've owned. And, despite my initial cautions, the Rotax 912S has worked out well as an ownership proposition.
I'm not suggesting that a solution like this is going to work for everyone, even for their Sunday burn around the patch. But there are some options out there and, while flying will never be cheap, some of the options bring the costs within the reach of those who might otherwise drop out - or never start.
I agree entirely re selling the GA experience; part of the challenge is just the sheer number of alternative activities available to young people these days. An observation I'd make is that the flying schools, in their understandable push for the CPL (and higher) dollar, often miss the mark in selling the PPL experience. I couldn't help but be impressed when I flew in to a country centre recently and noted the largish number of young people around on Sunday morning. The local schools do both RAA and GA training, with as much overlap in instructors and aircraft as possible, and have put a fair bit of effort in promoting their PPL and Pilot Certificate courses. I've got no idea how it will work out in the long-run but it's been going a while and seems promising.