Disclaimer 2 of the members are a 2 year old and a newborn and we have electricity only.
I pay weekly and it works out to be $38 pw so that's just under $500 a quarter.
Service and connection fees make up a bit of that
Edit- we have aircon, electric water and oven/ cooktop that does all our cooking. As we have TV shows that tape in the middle of the night we also don't but tv's on standby. In qld