Used Boat Hours?

How many boat hours is too many that you wouldn't buy? I've heard that if a boat engine is well taken care of they should last forever; on the other hand, I've heard that for a gas engine that 1000-1500 hours is about the time that an engine needs to be rebuilt depending on how it is used.

I'm currently looking at a boat that has all the additions I would like (v-drive, tower, perfect pass, ballast, updated upholstery) and looks to be in really good condition, but the hull itself has about 2200 hours and the engine was rebuilt at 1200 hours.