That sounds like a pretty good deal! Even if you have to do a few repairs, a driver for 400.00 that goes in the snow is good!
It could be the distributor - those distibutors are the cause of the problem pretty often on those years, but I would put a new fuel filter and check fuel pressure on it before I went and got a new distributor. If it has not run for a long time old gas could be part of the problem.
Factory service manuals for your truck are here:
http://www.nicoclub.com/FSM/Pathfinder/1997_Pathfinder/
Also, check out the general information sticky thread up above - it has a lot of info in it.