kickz101 is your first stop i'd expect. Elizabeth street in the city.
after that Footlocker Swanston street has a downstairs section dedicated to basketball. its the premier footlocker in the state for basketball, and generally if the shoe is limited in someway, swanston street will have it if any footlockers have it.
the Nike warehouse outlet in South Wharf is sometimes a good choice. the Nike outlet in Bundoora is a long way away, especially on public transport, but its huge and often has some good selections as well. you wont find jordan retros that often at the warehouses these days, but lebron and kobe are generally there.
welcome to melbourne. sorry about the public transport ticketing and the random weather. enjoy your stay.