We just found this noted on the Frequent Flyer Australia forums, that it's possible to fly SIN to SYD (via MEL) on Dec 28th from around $840. To put this in context, Jetstar is coming up at $1500+ and Malaysia 1700+ on the same day.
Not sure if mistake fare or not, but it's pretty incredible.
Alliance: OneWorld
Also SIN-MEL for $802, minus the MEL-SYD leg.
Edit: This stacks well with Amex spend $350 get $50 back. If you have the offer saved on two cards, you can buy a gift voucher to split payment across both cards, saving an additional $100.