I'm no KTM expert, but I do have a 95 version of the same bike. For what I use it for, I love it. I haul it to the trails on the weekends and can keep up (mostly) with my friends on 250 2-strokes. Then I put the mirrors back on and ride it to work during the week.
The engine is really buzzy on the road so I wouldn't want to do a long trip on it, and I personally don't feel comfortable doing more than 60mph or so. But for short commutes and trips to the trailhead it's perfect.
Parts are available, but the dealer won't carry them. If you can wait a few days, they can usually get them. Oil changes on mine are a huge pain, but I think the oil system on the 96 is a little different.
Offer him $1500 and buy it.