NT Skyline

Looking at buying my first car and have my eye on this: http://www.gumtree.com.au/s-ad/darwin-cbd/cars/r34-skyline-gtt/349640520 Haven't had a look in person, but apparently everything is stock. It seems fairly overpriced to me (he just brought it down from 16k). So, even though you can't tell much just from the ad, I was wondering what you guys think it is actually worth? Thanks for the help.