Very nice of you, I'm sure he'll really appreciate that. As for the truck, remember, this is a piece of fire apparatus. It may have low road miles, but as noted prior, we don't know if this truck had a pto driven fire pump or not. If it did, ,it could have a lot of engine hours on it.
Even if it doesn't, these trucks are run very hard or spend a lot of time ideling on scene, which is not good for a diesel engine. Depending on the department, they could sit a week without turning a wheel, then get a call and be out the door and flat to the floor with no warm up time.
Typically when a fire department sells a rig, it's pretty tired. The price they were selling it for may have refelected it's condition.
I hope it's solid for your friend though.