Where to find cheapest flights to oz this xmas???

[sqwerty]

We are looking to spend christmas in australia with family this year, just started looking at flights.
When is the cheapest time of year to book?
It will be 2 adults and a 2 and 3 year old, the cheapest im finding at the minute is still over 4 grand!
From manchester to perth, we can be flexible with the dates too we just wasnt to be there 3 weeks, roughly 15 dec to 5 jan
ANy tips anyone?

in my experience, book asap as you will be flying at peak times, the prices don't go down, they will only get more expensive. Sometimes the actual day/time you leave or arrive can make a difference, ie weekends can cost more also I think if you left earlier in Dec you may get the price down a bit?

I usually use expedia.co.uk or airline-network.co.uk