Get it looked over by a workshop before buying.
I know it is a long drive from Brissy, but I recommend taking it to Gavin Woods Autotech down here on the Gold Coast as he is a Nissan specialist. He does a full inspection (goes over the car with a fine tooth comb) and will tell you of any exisiting problems and ones that are about to happen, i.e like engine breathing, cooling system rusty, turbo shaft play etc etc.
They are all things that would breeze through a roadworthy but would cost you shit loads 3-4 months down the track.
My SAU $0.02