The 17-square-metre car space and storage cage was listed by R&W, allowing non-residents of the building to be able to purchase the space.
"Most of the car parking spots the strata reserves to the building but this one has annexed away from the building so anyone can buy it," Simeon said.
"So there are no guidelines restricting who that person is."
He said many families have a car they use Monday to Friday but some people were wanting a space to park their more luxurious car to use on weekends.
Simeon has never sold a car parking space before.
"It's a once-in-a-blue-moon opportunity... to purchase land in Mosman for just $10,000 per square metre is an incredible opportunity."
The space is 6.42m long and 2.75m wide and is located on the basement level of Bridlewood Gardens at 2 Brady Street.