The last time I asked (just before Xmas) how much it was going to cost to paint the 210 I was told nothing south of $25,000. Add on the inevitable other bits and pieces that will crop up and you won't get any change out of $30k.
I'd certainly agree with that. The last one I had painted was a few years ago now and was getting up there. Stripping reveals a multitude of sins. I heard of one that had some hail damage that had been bogged probably decades ago. Not a word in the logs. The painter was was quite happy to rebog it ... for another 6 grand. I dread to think what is underneath some of those shiny paint jobs. Always better to buy one with original paint if you can.
But is painting really worth it? Let's say you have a 35 year old 172, with maybe 6,000 hours and mid life engine and prop. If it needs paint, probably needs interior too, and windows. The avionics are probably boat anchors. Then there's SIDs (painting would be a good time to do that.) Would look nice.... But would probably not see it for about 12 months and not be worth what it cost. Dont even think about the misery of project managing some of those morons who make promises they know they will not keep. Better decision is more likely parting out or paint on most of those old planes.