Pay attention to the price spike beginning of 2009 (co-inciding with Rudd's billions in FHOG, RBA massive 7.5% to 3% rate cuts and the biggest spruike fest in human history).
By March 2009, the median price already fell to 650K from 850K eached in the Dec quarter of 2007 (that's about a 27% fall). If we are to reach that point from the peak in June 2010 of $1.07M, then the fall of close to 40%.
Now the big question is what price it would have reached on the way down back in early 2009 if it weren't for the gigantic reflation of the bubble. Perhaps $500K (which was already deemed expensive).
lets take a conservative view and simply assume $500K is fair value (which it isn't), we are then looking at a 53% drop in price if we fall back to this level.
BAD NEWS:
The problem this time (as compared to early 2009) is that we have a far more inflated bubble than the last time with much more participants, more glut and more "late entrants - FHBs and speculators like some on this forum" who will lose their shirts and their undies.
Also, given all busts overshoot on the downside beyond fair value, the suburb in question should instead be considered to hit a median price of $400K in the upcoming bottom.
