I agree with most of what transition_alt said 👍
I’d add or stress the following points:
Not sure what industry you’re in now but I’d imagine a similar rule applies. When you are just getting started it’s normally best to stick it out at the first job until you have something useful to take to the next employer. By that I mean 700 ish hours is not that useful in the grand scheme of things. However an ATPL is! The only way to get that is by passing an upgrade to Captain at Rex or Qlink. I’ve seen a former Rex f/o do exactly what you are suggesting, he paid out over $70K to go fly a Dash 8 for the same money. Went back to the bottom of the seniority pile and then left after 18 months anyway! The irony of it all was if he’d stuck it out at Rex he would have made it to the left seat by then....
Be very wary of any idea or way you think you can take a short cut or somehow ‘game’ the system. Although you have said paying out a bond is not a $$$ issue for you, I can’t see any upside until you’ve got a command and are then leaving for a jet f/o position. Sideways to another turboprop is a waste of your time and money.
As for Rex, Sydney and Melbourne are definitely possible if not straight away, you’ll probably only have to wait six months to get back there from somewhere else. Adelaide I’m not as sure about and Brisbane is only a small base so will be hard to get into. Also for your future planning Sydney is also where a lot of commands come up, Melbourne and Adelaide less, you can almost forget about a Brisbane command at Rex.
Basically if it is your plan to make the jump to aviation, there is no way to avoid at least 3-4 years of lower pay. Sorry but that’s the truth. Until you have a couple of years and 1500 or so hours under your belt the opportunities are limited.
But there is an upside. Opportunities like the Rex cadet scheme never existed when I started. It was ‘go north’ or flight instructing (on far less than $70K) in the capital cities, both of which don’t really sound viable in your situation. So if you manage to get accepted, work your but off and count yourself lucky you had the opportunity at all!