In the Uk we have similar debates.
Two very different scenarios in terms of threats but when you get down to it what really is the threat to Australia, I mean you arent going to fly them half way a ound the world to help us out are you.
From here it looks like Indonesia witha radical government in the future. maybe makes some sense
China-well if they want to make a move on all that space you have got a couple of smart fighters is not going to deter them is it. Basically you are toast before breakfast , but its very very unlikely isnt it?
Same here, who are the enemies, well its not the Russians anymore because they have already invaded England , well London , and they are more right wing than our Government is and all their allies are now our allies.
China is too far away so that leaves the EU and the USA who are traditionally on the same side . the EU military is about 5 times the size of the UKs and has the same or better equipment .
The USA , who knows with Trump, is equally unlikely and even if something did happen you can bet that a software intensive fighter would mysteriously stop working if used against its maker.
So define the threat first and then buy the toys -personally i think we in UK should have just stuck with our Typhoons and dumped the carriers and spent the money on more spooks and rapid response tactical level elite troops. And of course with the zillions left over spend it on such useless items as the health service, elderly care and better education but thats so boring. Maybe its different down there but seeing as you could give away the northern half of your country and no one would notice or care maybe you have some better alternatives too.