Fees associated - I have relatives coming from Hungary to Australia, with a 22 hour lay over

I have relatives coming from Hungary to Australia, with a 22 hour lay over in Beijing. We want to arrange accomodation outside of the airport for them to shower and rest and maybe do a tour, before heading back to the airport to head to sydney. I have extensively looked into the TWOV 24 hour, and understand its at the airport / airline discretion, But can't find further information if there is a fee associated with this visa application.