In my quest to find a Plane, I ran across this one:  https://www.trade-a-plane.com/search?category_level1=Single+Engine+Piston&make=PIPER&model=CHEROKEE+140&listing_id=2266334&s-type=aircraft
It's described as "Needs Paint
Student and hanger rash
Meant to be flown, not shown"
How does this factor into annual inspections or other issues?

Paint isn't structural...

That said, at first glance I'd worry that if the exterior was left to wither like that, there could be underlying corrosion or damage that has been ignored. Have it inspected thoroughly before buying.

It's also past TBO.

It might run another 1000 hours, it might blow up tomorrow.  That $12k plane just cost you another $20k.

ETA:  Also be aware it has substantial damage history from '97.  However, if it's been flying for 20 years since, it's probably fine.

That's another think I just can't get a grasp on: The cost of an overhaul.
I understand there are a lot of variables, but given a good core, shouldn't you expect say an O-200 "exchange" to run $X,xxx plus installation?
All the web sites I've looked at would give you a quote on a specific engine, but I don't want to yank someone around while I'm looking at multiple planes.
I suppose an estimate within a couple grand for say an O-200, O-290, O-320 and Continentals in the 90 to 150hp range would be helpful.
Also, while sophomoric: How many hours are you allowed on a Piston engine and Airframe?

I don't know the answer but there is/was a Cherokee on trade a plane with 18000 hours on the airframe.  I'm amazed at how many people don't respond to inquiries.  I'm guessing the planes sold and they can't be bothered to take the ad down.

When evaluating the condition of a plane, "needs paint" is easier to deal with than "new paint".

A new paint job can be used to hide quite a bit.  Smoking rivets will take a little time to start smoking again.  Bondo under new paint won't be obvious.  The 'shiny' also draws the attention of potential buyers and makes them less likely to notice problems that they would easily notice on a less 'shiny' plane.

An old paint job is going to have visual indications of wear problems (smoking rivets, any rubbing control surfaces, etc).  If there is any bondo under it, you have fair odds of it being easy to find, due to cracks or chips.  However, as previously mentioned, you have to watch for corrosion.  If you don't know how to spot corrosion, find somebody that does.

As for overhauls, the cost can vary from engine to engine (not just model to model).  Once everything is torn down, the crank may be too far gone, a case half may be damaged... or things could go well and there not be any unexpected parts added to the 'replace this' list.

I've seen O-320s go hundreds of hours past TBO, and I saw one of those planes get it's engine sent off to Lycoming for overhaul, then sent back to Lycoming just short of 100 hours later, because that 'fresh factory overhaul' engine started eating itself.  Engines are a gamble.  You improve your odds by taking good care of them, and you worsen your odds by treating them like crap, but they are still a gamble.

I believe most overhauls run 12-40k.  Like the poster above stated, alot of it depends on what parts can be IRAN'd and which have to be replaced.  

For Part 91, TBO is just a suggestion.  There is no 'required' OH time on most engines.  There could be some that are time limited, but I'm not sure.  Often, it's the insurance company that calls for an OH at a certain time.  Likewise, most airframes do not have a lifespan.  Cirrus specifies 12,000 hours, but that's not set in stone.  They don't have any real world examples at that many hours yet.

I fly, every now and then, a 172 that has 15 or 16,000 hours and has actually been in a midair collision that mostly ripped the empennage off.  You wouldn't know it when you fly it.

ETA: Here's an interesting site.  http://www.thisoldcherokee.com/

Kid bought a derelict 140 for $1000.  IIRC, he's invested WAY under $10k, including purchase price.  It's helpful that his buddies are all A&P's though....

Almost 9K TT? kinda high time I'd say. Remember when 2K was considered high time LOL.
Figure paint, most likely interior and engine your way up there money wise.  

Usually much cheaper to buy a plane with all that done by previous owner.

Ten years ago, I was working on a plane that had somewhere in the neighborhood of 25,000 TTAF.  For most of it's life, it had been a freight dog or charter plane.  9,000 is high, if you are looking for something to spruce up and make a nice plane out of.  If you are just looking for something to build time with, you are probably going to see a few planes with similar airframe times.

Saw quite a few planes come through Colemill that had been recently bought with new paint and interior done prior to the purchase, and the new owners thought having Colemill put factory new engines with more hp on them would be all that was needed to make them perfect (well, that and an avionics package).  Our code word for them was "creampuff", thanks to the company salesman coming down to tell us we had another "creampuff" scheduled for engines.  That was a guarantee of the salesman receiving some foul language in response, because his "creampuffs" generally turned out to be planes that had new owners worried about us scratching the paint, when they should have been worried about the hydraulic leaks, wires with insulation rubbed off or burned off, pneumatic systems that were shot, landing gear that needed to be rebuilt...

Last week, I had to repair some broken structure in one of the main gearwells of a plane that had been recently painted.  The landing gear was worn out and out of rig, and each time the gear retracted, it was beating on the structure (cracked the rails that held the bumpers that were supposed to take that hit, then started beating on the wing structure).

A couple months ago, a plane came into the shop for an annual, and it had just been picked up from the paint shop (paint couldn't be any more fresh).  First thing I noticed, was that the tail was going to have to be pulled mostly apart within the next 300 hours or so, thanks to an AD that requires some reinforcement of a bulkhead.  Then I noticed a few other things that were going to require some sheet metal work to fix for that annual.  We were scratching our heads a little, over the fact that the paint shop had removed some of the control surfaces to paint them, but left others on the plane while they painted them.  Turned out that the hinge bolts had rusted and seized in the bearings, and the paint shop chose to not deal with the problem.


Some people put waaaaay too much emphasis on paint.

This

Excellent Advice.

I was looking at that exact plane recently.

With some older planes it's just not worth it to ever repaint them. A 60's vintage Cessna 150 could cost you 15-20K and the cost to repaint it would be 15K.

fly's in, it'll fly out right?  

If I had a nickel for each time I heard that...

FIFY 

Hmm, I guess doing hydro dip or Cerakoting it is out the window because of costs.