I'm not quite sure it works that way (800USD=1200NZD) but for your USD budget I'd suggest: Dell XPS 17 Core i5 2.3GHz Laptop $$693
Core i5 2430M 2.4GHz CPU, 6GB RAM, 500GB 7200rpm HDD, 1600x900 LCD w/ GT 550M graphics.
With the optional GT 555M upgrade it would run $843 here.