If you shop in market then food is not too dear. Some supermarket quite cheap like Aldi and Costco offer good product at low price. Just need to do some research.
Certain top public schools are selective schools, students need to be top 5% or better before they can get in.
Private school has better funding from the government. They have better equipments and buildings as they can get funding from both the government and their archdiocese.
Some private schools are not that expensive.
Local private primary schools only cost $1k per year in fees.
Local public primary schools have fees of approx. $500 per year (when you include the P&C contribution etc).
For High School:
Mount St Benedict College at Pennant Hills
Cost is approx. $10k per year, this includes school fees and all excursions, only other costs are books and uniform.
Cheltenham Girls High School
Cost for yr 7 was approx. $2k when we include fees and excursions, other cost was uniform.