Some great solution from France to Australia is available with Etihad Airways / Virgin Australia. Round trip flights from Paris to Sydney are now starting at just €527. All charges and fees and checked luggage are included in base fare. Another option are return flights to Melbourne for a bit higher fare or even open jaw tickets e.g. Paris to Sydney with return from Melbourne back to France. Adding one more option to beautiful Tasmania (Hobart or Launceston) for very attractive €691.
Seems that the cheapest flights from Paris to Sydney are available from October till December 2016. Plenty of travel dates are available. To find the lowest fare available you may search directly at the website of the airlines.
Booking sample of cheap return flights from Paris to Sydney from €527! In this case you would fly from France to Australia on 30th of October 2016. Your return flight from Sydney back to Europe would be on 13rd of November 2016.