Planter...I dont know whether you fall in any of the categories but its worth a look:
www.travelclub.com.au - costs 30 bucks to join.....I have just booked Syd-Phuket direct for $399 plus taxes between 200-230....great deal but deal only runs through dec 3 to late jan....
Last time I used them I got Gulf air from SYD-SIN for $299 plus taxes 200....and yeah we took the asia air around midday and regret not taking the tiger air at 0700....our flight got into SIN at 0300...so it was a long wait...
other than that the best deal is gulfair to SIN for 665 plus taxes...so its much cheaper than the other options ie Sin and Thai airways...good luck