sa power is calculated over three tiers of rates.and you pay more in summer ie winter tariff/summer tariff.

winter
peak36kwh@$0.3150
next85kwh@$0.3179
next25kwh@$0.3500

summer
peak243kwh@$0.3205
next568kwh@$0.3519
next164kwh@$0.3844

then add gst
so qld power is a third cheaper.so i'm moving.
but then council rates up there really suck