Sydney is known to be a very expensive city and is up there with San Francisco and London.
As of March 2021, a one-bedroom flat in the city will cost at least $2500 in rent. Outside the city or in the western suburbs, the prices drop. You could find a one-bedroom for less than $2000 a month.
A three-bedroom family home would cost just under $5000 a month in the city center and just under $3000 in the western suburbs.