How a motor was cared for is way more important than how much time is on it.
I was with Champion from '84 until 2001. New boat every year, and took meticulous care of them, good fuel, good oil, and put between 450-550 hours on each motor a year. I don't know where every boat is, but I know where quite a few are, and every single one of those is still running. I truly believe the first two hours of use will dictate how it's going to live the rest of it's life. I broke every motor in hard and fast, and every one of those are running with well over 3,000 hours.
I've had more trouble out of my current 90 yamaha that had less than twenty hours on it, I've replaced every piece of ignition and electronics, every seal, every gasket, and every pump on it, simply from not ever being used.
So, long story...don't be afraid of hours, be afraid of upkeep.
Marble Falls/Seadrift TX