I feel for you!When I returned to NZ from Aus in "93, to eventually set up my own business, I was fortunate to have the highest x-rate, I think, up to now. NZ was fighting its way out of low economic growth from the 87 crash. Aus recovered a bit quicker hence the strong exchange rate. Possibly the shoe is on the other foot this time around.
History would indicate this situation will not last but for how long will Aus economy take to kick off? Or how long before NZ shoots itself in the foot? Labour Govt in power?
If you have enough money here how long are you prepared to wait?
If you waited and it went to parity would that stop you doing something here? Buying property, increase business expansion? This, to me, is the most important question.
If you brought your money over and invested it could you make more than leaving it in Aus?
You can always drip feed small amounts to cover increases but not take a major hit on the conversion rate. Do you intend to go to Aus for holidays where some money left there would make it easier.?
I am sure there will be lots of people to enlighten you on this site and good luck with adapting back to NZ life.