Not just that, it's a legal requirement that the price advertised is the price you pay. The ACCC will enforce this.
It's why, for example, the supermarket ogliopoly have a "if it's mispriced it's free" policy, they got fined for inaccurate pricing and tried to turn it into a PR win.
Airlines and ticketmaster are currently fighting to change it but now we have a less right-wing federal government again hopefully the ACCC will be allowed to do their job.