You have to pay the cost of the full foundation course regardless of whether you do the long or the short course; then, for those on the short course, the refund for unused time comes later. So it's still going to cost you an up-front payment of NZ$12,000 regardless of whether you have 80 hours or not.
Also, your PPL hours need to be fairly recent. Some people come out having logged 40 or 50 hours but none for a few years and take the long foundation course because the learning curve is quite intense and being on the long course helps.