Sorry for the late reply,
Perth is getting tight on pay in the city, but there is a fair bit of commercial work going on, the FIFO is also getting quiet, mining is in a bit of a hole (pun intended) but there is a good bit of offshore work coming in now as we approach the end of the cyclone season, offshore is not as closed a shop down here as it is in the N Sea, if you get your training in (not cheap) then if you are a scaffolder you will get work in WA.
Melbourne is busy in the commercial sector and there is a bit going on at Longford with CB&I (lots of beams), the unions are strong in Victoria so the rates are still high and Melbourne is cheaper to live in than Perth.
NZ is crying out for lads, and your Aussie passport and CISRS quals will get you over the line.
Good luck with it.