I can't give you specific advice but I can tell you a little about low cost carriers in the area.

the airlines to check out are(keep in mind Australian days and times):

Air Asia. you can also follow them on twitter and facebook so you find out quick for any offers

Jetstar. Jetstar has what they call the Friday fare frenzy but they don't do it every Friday. These tend to be after 5pm. Sign up for their email alerts.

Virgin blue. They have what they call happy hour each day at 12pm - 1pm AET (Australian Eastern Standard Time)

Tiger Airways. As with most of these airlines it pays to check their websites regularly as specials come and go very quickly.

another tool is travelzoo a weekly email alerting travel deals in the region. It has a site for Australia.

New routes are opening and they typically have amazing lauch deals you need to act quickly on.

Good Luck!