You have it exactly right. I drive my cars that many miles for work and at 200,000 miles you are approaching many costly maintenance items and possibly rebuilding the engine for a car that has a wholesale value of maybe a couple of thousand dollars even if it's in seemingly good condition. Because I use my car for work I'm not going to put the thousands of dollars into to it to maintain reliability which is essential for me. That's also why I way over maintain my cars with respect to fluid changes etc.
I wouldn't even consider buying the car we're talking about without a compression test and if it still has good compression I wouldn't pay more than $2000 for a car with that mileage knowing other major repairs are on the near horizon.
Once my 2019 gets to that point, it'll turn into a track car that gets fully built. It won't even be worth trading in or selling at 200,000 miles.