After 25 yrs in aviation as a commercial pilot, owner of several airplanes (one of which was a C 150 ), and married to an licensed aircraft mechanic I have learned a few things. The most important is the sum of the parts of a light US built aircraft (that is if you started with a data plate and then bought all the parts to required to assemble a whole aircraft) will cost about 10 times the cost of the aircraft. I have a few rules which I use to evaluate a potential aircraft.
1) The most cost effective approach is to buy the very best example of the model you can find, as this means someone else has spent all the money, not you.
2) If possible buy an aircraft with a known history.
3) Don't economize on the pre purchase inspection. The best way is to have the aircraft flown to your shop and looked at by your engineer. You may end up wasting some money paying for an inspection on a unsuitable aircraft, but that will still be cheaper in the long run than buying a dog.
4) For those contemplating their first aircraft I would also add 2 additional points
a) If it is not on the aircraft it won't need to be fixed. Be realistic about
your needs and stay away from fancy radio fits, constant speed
props and especially retractable gear.
b) Develop a realistic operating budget before you buy. Talk to other
aircraft owners and groups and find out what they have spent over
a multi year period.
The good news is my first four aircraft/aircraft shares sold for equal to or more than I paid for them so it is possible to have a happy ownership experience, not to mentioned the appeal of not having to fly clapped out POS
flying club rentals.