The day you buy is the day you sell.
All other things being equal, you are going to have an awful lot more trouble in a couple of years shifting the two owner high mileage car than you will the low mileage one.
Likewise, there is more to a car than the engine. There is the number of potholes etc that the car has run into and the way it was driven. High mileage cars have covered a lot of ground and therefore all the other components of the car, suspension, brakes etc. will have done a lot more work and would therefore be more prone to needing replacement sooner.
If I was doing high mileage I would imagine that I would drive the car a lot harder that someone who was doing less mileage as I wouldn't want to spent any more time in the car than was necessary, so I would accelerate and break a lot harder than the smaller mileage guy would not save the same amount of time rushing everywhere he was going to.
Also why do you think the manufactures limit their guarantee on a new car to 100,000 km or whatever, they know that after that that parts start to wear out.
Murt