Non-current, low-time, SEL-Instrument pilot here, but I try to follow general news and aviation, to please take my thoughts with appropriate grain of salt.
Seems to me a lot of the reason that the cost of piston planes has grown so wildly is what we now expect: perfect safety record (and assocaited liability risk and insurance costs), modern instrumentation and avionics, air-bags, parachutes, etc.
A comparison is that cars are no longer 4 tires, engine, windows and FM radio; they now have air-bags (with cut0ff switches) and expensive emissions control devices. There are few remaining VW's. The Army stopped buying $250k Hueys and $10k Jeeps, and replaced them with higher performing but costly $8M Blackhawks and $100k HMMWVs. In many cases these expensive improvements are good, but they are costly.
I expect industry (both cars and planes) is also at fault. US Automakers have little interest in producing a $5k car, even if they can, due to low profits. Is Cessna doing the same thing to aviation?
By the way, forgot to add in my earlier post that I've seen a very similar discussion among SCUBA divers. "Why is the gear so costly?". "We're pricing new participants out of the market", etc.
Similar liability issues. Less regulatory issues. Definitely 'technology creep', where manufacturers aren't content selling a $200 steel regulator built to 1980 standards, when a 2011 Titanium model will sell for $800, even though the 1980 model performed perfectly and was safe.
