True, the Illawarra would probably be cheaper. It's still hard for me to see it as a wise investment moving the entirety of the football operation to the area due to the amount of sponsorship dollars coming from Sydney.It's an interesting perspective. One more thing I think you are overlooking is that Illawarra is cheaper and most players want to live there rather than in Sydney.
I don't know if most players want to live there, it is a beautiful area but most players in general live in Sydney and Sydney has more opportunities, especially post football.