First of all, you can buy a perfectly safe and airworthy Cessna 150 for around $15k, and you could fly it from TX to CA - it would just take quite a long time,

First of all, you can buy a perfectly safe and airworthy Cessna 150 for around $15k, and you could fly it from TX to CA - it would just take quite a long time, and probably be quite bumpy. You might also get stranded for a few days half-way while waiting for weather. To fly long cross-country trips in comfort you really need something like a Cessna 182, or even better a Cirrus or a light twin. You'll end up spending at least $100k for well equipped IFR plane (and you'll need an instrument rating). Ideally you'd want oxygen, turbos and deicing so you can fly above/through the weather. So, in summary, it's not really feasible to buy a plane for personal transportation across large distances unless you want to spend a lot of money. You just can't beat the airlines in terms of value for money, safety and reliability, even if it is a miserable experience.