The sale says tickets are from $479 including fuel surcharge. When I searched earlier today the lowest overall price from Brisbane is $606.32 ($480 for the fare, $126.32 for taxes). Melbourne departures are available from $586.70 (taxes $106.70). Available for flights booked by 16/2/09, departing between 2/2/09 and 31/3/09. For full terms and conditions of the deal, see http://www.emirates.com/au/english/destinations_offers/special_offers/special_fares/160209/ben(mel)_sin_e_310309_160209.aspx
This is about the cheapest I have seen for some time for flights from Brisbane to Singapore return, and is not subject to a 2-for-1 condition as with some other specials. This is a great price for a direct flight with a full service airline - at about 50% off the normal/full price, and probably cheaper than budget airline options (I recently did Brisbane to Singapore with Airasia - Gold Coast to Kuala Lumpur to Singapore, ie one drive, two flights, waiting/transit time etc - for a bit more than this sale price, albeit during peakish season).
The booking site is horrible..