If:
No rust.
Starts easy and runs/shifts smoothly through all gears in both ranges.
Idles smoothly and quietly.
All gauges and lights work correctly.
Stops quickly and evenly.
U-joints and rearend output pinion are not sloppy.
Steering feels good and the truck tracks straight.
Tires have good tread and no cracking in the rubber.

It might be worth the asking price.