Yes, i've got my PR.
Well, i did some research and based on my friend situation.
So far, the info i have is daycare cost around AUD75 (the cheapest i can get), others might cost up to AUD200/day. If your wife is working then you have to make sure her income is enough to cover. If not, no point to send kids to daycare. DIY
Living cost in melb & syd is pretty high. Accommodation is damn high.
In perth. housing is the main concern. You can get a bungalow with 4+2+2 at AUD400k which depends on location. If you're earning 80k for a family of 4, you have to pay more attention in every cents you spend otherwise makan rumput...
Think for long run, if you're looking at melb & syd, probably you'll be buying townhouse or apartment. If you're aiming for bigger house, think perth, brissie, adelaide, darwin & tasmania??? It's cheaper a little....seems whole australia is on a property boom.
Compare to KL, buying a bungalow it's more than RM2mil which is AUD 700k

even though im planning to migrate to australia, i dont think i would buy a house. too restrictive on my freedom. anyway, everyone will have their own preference.
hopefully you will update us when you are there.