I bought my 63 Cherokee 180 from an A&P and it had just been annualed by another IA. Despite that, (and the pre-buy by my AP/IA who is meticulous and I trust explicity) I am still finding things like hardware/automotive nuts and bolts that I am replacing. Corrosion that was hiding and needs remediated. Then there are items that should have been taken care of at annual (brake pads worn beyond limits and cracked bracket). Add to that, a failed TC, Horizon and Mk12D, and when I am done, I will have another $3K into my "great deal" PA28-180. Despite all that, I still have a 175 hour engine with new or rebuilt components and a $40K all in after the repairs, a pretty solid airplane.
My point is, no matter what you buy, you are going to put money into it. Just get a good deal on a basically solid airplane, and stick the savings into your pocket for the repairs you WILL be making. It's just the way it works.
Good luck.
