A three-storey penthouse at the top of James Packer's proposed Crown Sydney hotel and casino resort at Barangaroo could be the first Australian property to break the $100 million price barrier, a leading agent has suggested.

Such a result would mean with a single apartment sale Mr Packer's company Crown could recoup the entire $100 million licence fee it has paid the NSW government for the right to operate a VIP-only casino in the facility.

High life: an artist's impression of the top of the Crown Resorts tower.

Crown has yet to even lodge a development application for the proposed 69-storey tower but last week the architecture firm which designed it, Wilkinson Eyre, revealed the latest plan for the three uppermost levels.

"Right at the top we have three floors as one apartment," company founder Chris Wilkinson told a gathering of the property development industry in Sydney.