Don't know about city airport AROs. But most FIFO/mining ARO's can expect to earn $95k-$130k a year doing either 8/6, 7/7 or 5/2/4/3 roster.
ISS, ESS, Sodexo mainly do 2/1 rosters earning $65-$80k a year.
Main issue with getting a catering company to manage your airport - the NCNs!!! Just because you have done an ARO course and have been with the company for so many years, doesn't mean you can actually manage an airport. Albeit, a small certified airport with a few charters a week.
CASA (in WA) are not huge fans of these catering companies doing the ARO work at airports. As they don't have any back office support, or their line manager is all about saving money. Rather than providing a safe service.
Most mining companies will not only offer even time rosters, but also 5-6 weeks annual leave