Mate, try the AirNZ Flying Club, they operate not-for-profit, have a C150 ($130/hr), C152 ($140), C172 ($150) and a C172RG ($160). Cheap annual fee of $90 or so. Online booking system, and you just come to an arrangement with the instructor if you need some dual.
Air New Zealand Flying Club
Otherwise I know of a private C152 Texas Taildragger aerobat at Rangiora that could be avialable.
S2K
Disclaimer: Rates may have changed since I last saw them. not by much if they have I'd think..