When we began considering the move here back in 2000, I used another forum site (only found this one later) and people were asking what to do once they'd bought a house outright (no mortgage), how should they spend the rest - jetski's, boat, new pool in the garden, investment property etc... All sounded stressful, funny how things change.
You come with what you can, and you manage... that's it I guess. There is no real cut off, as there is always a way. :)
If you are PR (and maybe other visas), if you have kids you will get tax benefits, rent assistance etc... you'll already have income. Best bit, if you time it right, you'll get tax back from the UK and not pay any tax for the current financial year in oz.