From my perspective - out situation was a little different to yours in that we were renting in the eastern states (inner city suburbs in both Sydney & Melbourne - 10 mins train trip to the CBD in both cases) - had an awesome lifestyle. We moved back home to Adelaide in order to "be able to afford a mortgage" cause everyone knows living expenses are cheaper in Adelaide......biggest falsehood out there!
Yes, rent/mortgage is cheaper, but the salaries are so much lower, so you don't get the benefit of the lower mortgage. Add the fact that electricity, gas, water etc is more expensive in Adelaide than anywhere else in the country, & financially we are far worse off than what we were before.
Sure, we're near family now so have babysitters, but we can't afford to go anywhere!!!!
Financially we were far better off in both Sydney or Melbourne, our lifestyle was way better, & we were flying home once every three months to see out families anyway, so we still had good relationships with everyone.
Personally I am now of the opinion that the dream of "owning your own house" is overrated, if it means you can't afford to enjoy your life!
I'm not sure what living expenses are like in Brissie but it's worth some research before you make your decision!
My advice to you is work out your most important motivator for your move -- be it housing, financial, family, friends, whatever -- and that will help you decide.
Good luck, it isn't an easy decision!!