The attached is from the Tesla Australia website today 21 January 19. The calculator assumes $1.15/litre - in really today it's $132.3/ litre. Since the SC price hike - this is not really truth in advertising. I have free supercharging - but at these costs less people are going to drive EV's. I know most charge at home, as I do - but supercharging prices are now an incentive for flat earthers to stay with ICEs.
I don’t imagine supercharger will ever be as cheap as charging at home. I don’t mind paying for trips. I prefer the super chargers are plenty and available instead of free.