How Many Operating Hours Are Too Many for Used Equipment?

[Grab_a_Buck]

I'm shopping for used heavy equipment and keep wondering how many operating hours are considered too high. I know it depends on the machine type, maintenance history, and previous use, but is there a general limit you try not to exceed? Have you bought a high-hour machine that turned out to be a great investment, or did it end up costing more in repairs? What hour range do you personally look for when buying used equipment?