I have got nothing to do with PAC Blue, but the only thing I can comment on is the cost of living in AKL.
Housing expensive. Cost of real estate is similar to OZ major capitals with the only difference it's in NZD (which at the moment is about 30% weaker than AUD).
Food and utilities not too bad, comparing it to OZ, its much cheaper.
Cars are very cheap to buy but fuel is very expensive, approx cost of 1L of unleaded 91 is about NZD$1.60-1.70 it has been above $2.00 within the last 2 years.
In terms of tax, I would imagine your FO salary would most likely put you into the 25-35% bracket, I have heard recently there is talk of tax reduction though. At the same time GST is being increased by a couple of % in the very near future.
Just my 2 cents worth,
Good luck!
C