i like mine. i've had a boatload of problems with my 2000, but from what i've heard, i'm the worst case anyone has ever heard of.
while it was still under warranty (up till 60k extended warranty) it took: 2 transfer cases, entire front axle, rebuilt rear axle, drive shaft fell out at a stop light in city traffic right outside washington dc, fuel pump, gauges, oil pressure thingy, airbag module, PCM, engine bay wiring harness, TCU, handfull of CPS and TPS's, exhaust mainfold... its left me stranded at least once a year since i got it new, in 2000.
i doubt you'll have 1/5th of the problems i've had. i think it was probably a fair deal. i don't see 2wd XJs commanding the same kind of money as 4x4 models.
one bad thing is if this vehicle will someday turn into a jeep built for speed, the exhaust mainfold is going to be very expensive to replace. most 2000 and 2001 XJs have 3 catalytic converters, two of which are integrated into the exhaust mainfold, making for a costy replacement.
as far as electrical gremlins, i've heard about them more for 1999 models, they had problems with the gauges not clipping into the wire harness very well, giving crazy gauge readings. i've never heard of this on 2000 models, but if this vehicle is an early 2000 model, it could have some of the 1999 parts bin leftovers.