Anyone who has tried to buy or rent a property in Sydney will know it is ridiculously expensive. You are basically looking at $500 a week to rent a shit-hole apartment or $500,000 to buy a shit-hole apartment. Not good.
Economists will tell you the high prices are due to a problem of under-supply which is not precisely true. It is actually a problem of under-utilisation. In Sydney there are are a ridiculous number of massive houses with just one or two people rattling around in them. If we wanted to instantly solve Sydney's housing shortage we could just pass a law saying that you must have at least one occupant for every bedroom in your house or pay a large tax.
All of a sudden home owners would be taking in boarders or downsizing to appropriately sized properties. Rents would drop ridiculously, students could afford to study and young families might actually be able to afford to live in a family home without both parents working their arses off and never seeing their children. Everyone would have more disposable income and we could afford to buy overpriced coriander at Coles. It would be brilliant.