Experts and medical practitioners are predicting up to 70% of the Australian population could be infected, with lower bound being around 20%. I don't believe this takes into account any critical statistical analysis and instead is being predicted based on limited data points. Even 20% of the population is 5 million people, which is a ridiculously high number given the density of the Australian population. Hence there is a strong argument to be made that the final number will be in the hundreds of thousands, if not the tens of thousands.
Challenge Neeharika Prasad to a bet on this prediction!