Don't underestimate the treasure trove that is "hard waste collection day" here in Adelaide too! Take a drive round some of the posher areas of town on hard waste day, and it's amazing what you can pick up! Should be able to get a couple of chests of drawers for your kids and all sorts of other gems if you're lucky!
At the Adelaide Festival the last couple of years, they have had a "Hard Waste Cafe" set up in the parklands, completely furnished with sofas and chairs and bits of carpet that have all been collected from the roadsides for free in this way!
Garage sales are another good source.