One has to go back 16 years for the kind of luck you mention, even then, the price of an average Melbourne house was four times average wages/salary. You have to go back 27 years to be able to say you got a good deal at three times earnings.
RE: So how come all of those on HC over the age of thirty one have'nt got lots of properties.
What kind of a sane 21 year old wants to buy a property, sure, have a savings account but not a rope around your neck - remember: you don't own property, rather, property owns you.