I've been buying high mileage vehicles successfully for a long time now.
My truck now has over 400,000 miles on it. I bought it when it was 5 years old with 280K. It only had one owner before me.
The way I figure, the only way to put nearly 60,000 miles per year on a car is to spend most of your time cruising the interstate on cruise control. That's a pretty easy life for a vehicle. Trans never shifting, engine rpms steady, no hard cornering, minimal wear on brakes, etc.
Owners seem to think that the minute a vehicle hits 100K the doors are going to fall off. Prices reflect this.
High mileage vehicles are dirt cheap. I buy them prepared to put some money into them, and then fix them right. So far, I've had great luck with quite a few cars.
When I bought my truck, I thought it might need a transmission because it shifts funny. I was prepared to spend $2500 on a trans. But even with that, the purchase price of $7500 was well below comparable low mileage vehicles of $18,000- $22,000. I figured I could dump $2500 into it and still come out ahead.
I never had to put in a transmission.
Older vehicles have much worse problems. Multiple owners, multiple driving patterns, repairs (some good, some bad), and the ravages of age (rust, deterioration, etc.).
I LIKE older vehicles (for design, simplicity, maintenance), but I prefer buying high mileage ones for reliability.