What are average house cleaning costs in Sydney Australia? ?

What do people here usually pay? If the cleaner sets aside one day a week for our house it doesn’t seem fair to just pay an hourly wage. We want the house cleaned weekly even when we are away. In which case they may only need to clean for two or three hours.
We have a large house with plants to water, outdoor and indoor kitchens, outdoor laundry, pool tiles, pool furniture, glass pool fence, large balconies, 4 bedrooms, 2 offices, large gym, 2 large living rooms, tiny game-room, small sitting room. We are out of the country a lot and so for much of the year they would not need to do a lot indoors. We want a couple or one person not a service so that may be more expensive. We don’t want a service as the cleaner/s will need to enter the house when we are gone, and know security codes etc.
Also are you legally required to tell cleaners about security cameras etc. in Australia?
We have a lot of very expensive art and a few museum quality artifacts. We would worry about people we didn’t know (such as cleaners working through an agency having keys, alarm remotes and codes) I have been quoted $120AU per week from one couple plus $450AU for a one time complete clean incuding exterior and interior. I am speaking with a woman that owns an agency but still cleans homes herself and may be able to talk her into cleaning ours herself.
Our house is very large and seems to get dusty very quickly. We have a lot of indoor plants that need tending as well. When we are away our house would still be hard work because the outdoor kitchen is exposed and needs cleaning every week.