I was curious, so I asked an AI (Gemini) to compare the wholesale price of electricity in Ontario vs Sydney, in Canadian dollars, including any subsidies in the price. The reasoning is the wholesale price best reflects the cost of production.

The outcome was surprisingly close. Sydney seemed to be a little more expensive, with a spot market average of CAD$73/MWh vs CAD$65/MWh. A wash really.

I don't know what is going on with the retail prices. My rule of thumb is multiply by 3, but your multiple is closer to 4.5. I live in Brisbane for example, where the average price is $100/MWh and we pay around $.30/kWh retail. Have you looked at https://www.energymadeeasy.gov.au/ ?