Prices are around €2300 (£2000) to Melbourne or Sydney.
The fare rules are:
Tickets must be issued by 16th November
Travel must commence by 30th September 2019
Stopovers permitted (one each-way) at €100 each
You may need to play around with your dates before you can find this price. Here is an example I found on swiss.com for May at €2350, which lets you fly on Singapore Airlines for most of the trip (click to enlarge):
Of course, in that example you need to get to Paris and then change in Zurich and Hong Kong / Singapore so it isn’t the simplest routing even though the comfort factor is high.
If you don’t have a credit card with 0% foreign exchange fees, your best option for paying is American Express Preferred Rewards Gold which offers triple points – 3 per £1 – when you book flight tickets in a foreign currency. This is because the transaction triggers the ‘double points for airline spend’ and the ‘double points for foreign spend’ bonuses. Our review of Amex Gold is here.