I am looking at possibly buying a 2002 npr hd dump truck 4 cyclinder diesel. I dont know alot about these trucks and could really use some advice on what to look for. I test drove the truck today and it starts right up with bo leaks on engine or hydraulics . Steering definitely had some play, and could use a brake job. Steel bed has a new floor but still has rust issues on sides that has been painted over recently. The truck reads 115000 miles on it, but feels like it has been driven pretty hard for that many miles. The a/c is also broke.This truck has a crew cab witch is a must for me, and are also very hard to come by in my location and price range. They are asking 16,000 and most of these trucks (although in better condition, but with more miles) are going for 25,000 to 30,000 with a crew cab in my area . I have no idea how well it was taken care of as far as oil changes. Should i buy for 15,000 cash and take the gamble or put the money as a down payment on something more expensive. Thanks for any input