This all depends on whether the airlines are having seat sales, and where you are travelling to. You would most likely need to purchase the tickets a couple of months in advance.
Start looking around for some prices now, that way you can get an idea on what the standard prices are, and you will know when a good deal comes out

Flight Centre usually has the most competitive airfares out of Australia. Check out their website:

You can also check and see what they have to offer.

Make sure that you understand the rules and restrictions of an airfare…something might be a couple of hundred dollars cheaper, but have a whole list of restrictions that may cause you problems down the road if you need to cancel and/or change your plans. You should also pay the extra money and purchase cancellation and trip interruption travel insurance

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