Hmm, Nissan Z's are actually a completely different car to the latest Skylines. Similar engines, but different cars. It's actually a Nissan 350Z which is the latest in the the long line of Z series cars such as 300ZX, 280 ZX etc. They have nothing to do with Skylines as far as I know.
Perhaps the new Skylines are rebadged as Infiniti in the USA, if that is the case there is NO WAY I would spend $50K US on one, NO WAY. Personally I'd much rather find an R34 GT-R Skyline, a 98 Twin Turbo Toyota Supra or an 98 Twin Turbo Lexus Soarer. I don't know what they go for in the States, but you can find a bombed out Supra or Soarer from those years for around $30K AUS and a GTR for about $70K AUS. You would have loads of money to spend customising your car with better paint, interior, sound system, rims, tyres, exhausts, kits and everything under the sun. I have friends that have gone out and bought GTO's for $60K and my car looks better than them, is faster than them, has better sounds than them for like 25% of the price.