Fair; I guess I should have run some data. I just used gasbuddy.com to run a similar track for what would have been my rather lengthy commute if my employer had asked us to return to office (and kept the lease on that building). Apart from a couple of outliers just outside the Dallas-Fort Worth airport, I'm only getting an 8% variance (about USD 0.23/gallon, versus your 25% and AUD 0.55/litre -- is that right?).
That said, Iwill admit that $0.10/gallon suboptimal average price is probably more likely than I thought, though with a less intense driving situation one would still be well under the $260/year "convenience premium." Outside the US and other oil-subsidizing countries, the numbers clearly work out very differently.