It depends where you live.
DS goes to 3yo kinder, and its 880 a year, paid in 4 installments for 4 hours a week.

4yo inder will be about 800 a year, for 12 hours a week - its cheaper becuase its govt subsidised.
If you have recieve certain types of FAO or centrelink payemnts (cant remember which) you can get 10 hours of 4yo kinder per week for free.