Average income in 2017 is not 55k, it's $75,275 for South Australia.
You're not even close.
http://www.abs.gov.au/ausstats/abs@.nsf/Latestproducts/6302.0Main%20Features5May%202017?opendocument&tabname=Summary&prodno=6302.0&issue=May%202017&num=&view= Bzzzzt. Wrong. That's average full time earning. You think everyone works full time?
Cmon mate. Surely you've seen enough .6 and .9 contracts down your way.
http://www.abs.gov.au/AUSSTATS/abs@.nsf/DetailsPage/6302.0May%202017?OpenDocument
Avg for Australia is 60k, SA is 55k. (I think this was 2011 census though, probs higher now)
In case you couldnt be naffed doing the calcs, here is something lifehacker prepared earlier:
https://www.lifehacker.com.au/2017/05/how-much-does-the-average-australian-earn-in-a-year/
My bad, I assumed that if you're working less than full time you don't have a right to complain about any affordability issues.
Probably naive of me to do so.
I would be interested to see the difference in the number of breadwinners in a household between 1990 and 2017.
IE: I'd assume in 1990 less people worked, but those that did worked closer to full time.
As you say, now days there are a hell of a lot more .6 type roles available as workplaces become more flexable, but these are generally the second breadwinner in the household.
So before mum stayed home and dad worked 1.0, now days dad say works 0.8 and mum 0.6 and overall they are actually better off with 1.4 vs 1.0???
(I haven't looked for data to back that up, just a gut feel).