$17k is a little pricey, i'd be dubious of the km's. But if you want a clean unmodified version, and an independent vehicle inspection gives it the tick, then you might just have to pay the extra $$$.
Have you considered other skylines? Early model R33 GTR's are cheap theses days if you want save some extra $$$, older cars, but much better bang for buck comparing stock for stock. A few mods on the GTR will go a long way.