Please give some flight suggestions to travel to Sydney from Kuala Lumpur via Gold Coast/Melbourne?

I flew from Gold Coast to KL and back last August with Air Asia. I paid a total of $456 for two single tickets. I stayed at YHA Coolangata before my outbound flight, which was conveniently located next to the airport. The Air Asia booking site is very frail so be patient with it. KL's awesome. Have fun!