Welcome to the forum. It took you long enough (almost 13 years) to make your 1st post

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I have a few suggestions. I'm sure other members will have more:
* If possible, the A&P that does the pre-buy inspection should not be the same one who has been taking care of the airplane. Needs a new set of eyes. Besides, not everyone is good at critiquing his own work.
* Ask the seller if he would agree to have the pre-buy conducted as an annual inspection (you can offer to split the cost of the inspection, not repairs, with him). That way, there will be definite pass/fail criteria according to the FAA, instead of "it looks good to me".
I didn't follow the first advice when I bought my plane, because I didn't know any better. Fortunately, the A&P was an honest one. I ended up using his service during the 16 yrs that I owned my plane.
I did follow the 2nd advice. It turned up about $800 worth of needed repair (control yoke U-joint, a few other things). I used that to bring the selling price down.
If you're not concerned about other people buying that plane ahead of you, post where it is, or its general area. Some club members who live near there might offer to take a look at it for you.