Not blaming anyone here - but the full mortgage deduction is a real rarity outside the US, and people seem to be able to buy homes just fine. What you do have in some places are savings plans to help young people save up the down payment for a house. Don't know what (if anything) Australia has in that line - but you may want to consider renting for a bit before taking the plunge to buy a house.
Cheers,
Bev