I'm pretty certain it's $90 or more a month. I did a quick Google to confirm but couldn't actually find that confirmed though.
After Optus made it $15 a month on top of your bill this year it made my $70 a month plan $85 every month, I changed my plan to the $90 plan, get an extra 7gig of data a month (I was already going over the old 4gig most months) and then didn't have to pay for Optus Sport anymore. Only making my plan an extra $5 a month. If that makes sense ahah.
I’m pretty sure it’s less than that. The $30 sim only plan, then $15 per month for Optus Sport is the cheapest. They had a special recently for like $18 per month if you did the trial, but think that has expired now.