It's exactly the same content. They're all Fairfax. You can take any smh.com.au article, replace "smh" with "theage", "brisbanetimes" or "watoday" and see what I mean.
If the subscription prices differ among the cities, go with whatever is cheapest. You'll get them all.
More to the point: do they provide any articles worth reading? Most of the content is either news available with less exaggeration via ABC, or fluff / outrage pieces that aren't really news anyway.