That Frontier looks like a very good deal. The 5-speed manual transmissions in them are fantastic (unlike the automatic grindbox that I unfortunately am stuck with...until I can get my hands on a manual from a 90-95 Pathfinder, that is :jumping: ).
The VG33E, the motor in the 1st generation (D22) Frontiers, (WD22) Xterras and early 2nd generation (pre-2001 R50) Pathfinders, and the later Quest and Mercury Villager minivans, is an incredible motor. It may not be the most efficient, it may not make the most power or torque, and it is probably heavy enough to be made out of dark matter...However, on the other end of the spectrum, it is one of the strongest, and most reliable motors Nissan has ever built. It is derived from the VG30 motor used in almost every 300ZX, early Maxima, early Pathfinder and Hardbody pickup, and the earlier Quest and Mercury Villager minivans.
I have read reports of VG30 motors lasting over 500,000 miles with no major issues. That Frontier looks very well maintained. I highly doubt you'd have any major issues with it.
I've got just under 130,000 miles on my `99 Pathfinder (same motor), and I haven't had any problems with it that weren't my own darn fault. :Mechanic:
(Wouldn't it make a little more sense to have a Truck on that smiley instead of an S4? LOL)