in Melbourne as dirge said, you can try HYPE DC i'm sure you have seen em around
Also try General Pants.
You can also try Carhartt in Melbourne Central (near T-Bar), Platypus also in Melbourne Central near Elle's ice cream.
Now in little la trobe st (road your RMIT bookstore is in) there is HEIST which has pretty sweet stuff (thats where I scored my B-Bot hoodie) http://www.heiststore.com/
If you are on Chapel St there is Dakota 501 on the corner near the new footlocker (across road from Jam Factory)
Good luck hunting ey