AirAsia sale, found through FlightScout
Details:
From: Perth
To: Bali
Dates: Sep-mid December
On: AirAsia
Carry-on only, but this is to Bali, you don’t need much, and you can buy anything else there.
EDIT: some people struggling to find the price via FS (through to other OTAs) but the price within a dollar or two is also available directly on AirAsia.com – you might need to be logged in to your Big Member account to access the prices.