As owner of a 2003 Mercury Marauder that has nearly 250,000 miles I can speak from experience. Some people say that anything with over 200,000 miles is a ticking time bomb and others say if it exceeds 200K, it’s because it was taken care of. I’m a believer that everything depends and there is no set answer for this. I have seen cars with over 300,000 miles look nearly show room new and I have also seen cars with 14,000 miles that look like they are ready from the crusher.
If the car is a one owner with 200,000+, I believe it’s because it was taken care of. This is in exclusion to company vehicles, those must be taken care of to keep business running, literally. Depending on the car, we can expect typical issues that have been proven to happen. Porsche 911s with a transmission leak around 110,000 miles in the late 90s and Ford Crown Victorias with the intake manifold going out 150,000 – 180,000 miles for examples. If these cars went past these miles, I would see that the car had been taken care of and these issues have already been addressed. A car that is near the mile marker of typical issues would have me stray away or talk the seller down explaining how the issue will cost thousands when in reality I can fix it for 1/10th of the price or less if I do it myself.
In conclusion, there is no sure answer if you plan on buying something with this type of mileage. Do your research and ask questions. If you plan on exceeding 200K on your own car, be ready to take care of it and be sure to look up what to expect other than tires, belts and hoses, those are a given.