We have owned a bunch of big frame Challengers which were basically the same machine when they left the line.  One was bought with 6k hours.  It had been on a scraper.  Needed a little TLC.  One was bought with about 2k hours.  Had been used, but didn't need anything beyond regular wear and tear.  One was bought with 4500 hrs. Had some paint that had been installed recently, and clear sprayed over everything.  Had also done some construction work.  One was bought with 2700 hours and was really pretty condition.  One was bought as a new tractor with a few demo hours on it.  


We've had to put a set of gears on the front drive on the engine on one.  Rebuilt a transmission.  Replaced a  Lourdes coupler.  Replaced a fuel tank for leaks. Various other stuff done over the years that I would consider routine wear and tear...belts, midwheel bearings, hydraulic couplers, and have rebuilt every single hydraulic stack in the fleet at least once.   

Now guess which one has had the engine work and the transmission rebuilt.....it's the one that we bought new, that has always been babied and kept pretty from original,  driven by only a few people, had 5 year extended warranty (which paid for the engine work)  has never been hooked on a scraper, and with the least total hours on it.   Go figure. 

Friend of mine who used to be buying 5-10 used tractors a year told me that the best deals were ones you bought at a discount because they had something wrong with them...there's a percentage where the problem is actually something minor and you end up with nothing in it.  The 'good' ones still have a failure rate, and it really hurts to pay a premium for something and then have it not last long enough to earn it's keep.