I cannot help you out with local mechanic but I can give you some ideas of what to watch for.
I had a 66 Cherokee for 8 years and 880 hrs. Very affordable maintenance wise.
If you see blue under the wing then you might have leaky gas tank. I think they are $800 ea to seal plus RR.
The last two ad's for Cherokees include: yoke control cable check and stablator horn control cable and hardware.
They usually have bendex mags which are easy and inexpensive to OH but I do not ask for OH I ask for IRAN instead. Cost me under $250+$275 for both have both done. Starter rebuild or IRAn was $175. I think the most expensive accessorie was a new carb for $340. These things are usually new with a new OH'd engine.
Tires and batteries are something a pilot owner can change out and buy cheaply at Aircraft Sprouce or other locations. TAP or trade a plane is the parts source bible so its worth $36 per year.
If you are lucky the Cherokee you are buying has an oil analysis history to see the trend of medal which tells you about parts that are wearing heavily. Should be small changes between each oil analysis.
also hopefully the plane if flown regularly the last two years. If not it could cost a bit more to get things going again.
Good luck feel free to ask for any questions you might want answered. If you rather you can PM me instead of posting publicly.