I was biding on two M1008s, side by side (twins), one was listed as 28K and the other listed as 82K. I wound up taking the 82K as the other bidder went sky high!
When I was on the GL lot loading mine up, we popped the hood and cab of the 28K and looked around. I was glad that I got the 82K, the 28K had not been rode hard and put up wet, but was showing serious signs of disrepair. The rubber, hoses and gaskets, were crumbling, the guages were glazed over, and the seats were almost gone - all from the sun and elements.
Go and take a look at some of the civy counterparts and you can get an idea as to the condition, aka mileage, of the steed you are considering. You have to look at everything, not just the odometer...
Good luck and if you decide to pull the trigger, please post pics and video!
Good Luck!