Edit: Marked expired as it looks like sold out on SYD-MNL. There are still many very good domestic fares available in PH and maybe other international legs - I haven't checked but good luck ;)
Cebu Pacific is having another 1 peso fare sale - basically same as my previous deal in February. All routes (except SYD-MNL) are 1 peso PLUS admin fee and mandated taxes etc. This is literally as cheap as their prices get and only a few times a year.
Sydney to Manila is $109 one-way.
Manila to Sydney is P2200 one-way (about $60).
Previous deal - https://www.ozbargain.com.au/node/290565
Book are two separate trips for best rates if starting in SYD especially.
Obviously use Bankwest Platinum, 28 degrees or Citibank Debit to avoid cross-border/comveraion fees. I'd recommend Bankwest Platinum personally for the travel insurance (I don't have a 28 degrees so not sure of any cover).
Site is currently struggling badly (it is at least from here inside PH), not sure if they give any extra preference to traffic from outside PH or not.
From past experience there won't be that many dates but they are defineitly available - just need to find them. There will literally be no availability near Christmas/New Year.
Travel dates are 01/09/2017 to 15/03/2018.
Probably of most use if you are completely open to any travel dates - once you find flights SYD-MNL. Then consider booking (separately, id leave it a day or two myself) to an Island or even onto Hong Kong, Dubai, Taiwan, China (or any of the usual Asian cities that they fly to). Manila is reasonably safe (not the horror story you read about I can assure you), traffic is awful - but it's a good stop over for a few days for sure.
Sale ends tomorrow. Hope someone can find a bargain ;)
I just booked three internal flights. Total cost ~$24. No luggage as yet, but you can add that later.
I bought two of the $170 return trips back in April so they are both shaping up as very cheap holidays.