Do you know if the radiator has been replaced? Just asking because it looks original in the picture. As with any vehicle, as radiators get older they are a geyser waiting to erupt and the failure of a relatively cheap part can cause expensive repairs (i.e. head gasket or worse). Maybe this is a good sign, and opportunity to do some preventative maintenance. Radiators are pretty cheap for these, I've done a few, and they are an easy replacement.
You should also, if it has not already been done, look at the hoses, fan clutch, and thermostat. In total, assuming you do the work, your looking at around $300 (give or take a little) for parts. What you get is cooling system peace of mind, both on and offroad. Sorry for going of on a tangent here, but I've seen a number of these fail and cause expensive repairs.