The problem with this is twofold: cattle - we are already supplementing one of our teams with foreign players in the twilight of their careers; and financial - that's a large wage bill, even with private investment.
What?
The whole point of privately owned teams is that it costs the Unions nothing.
If the Super Rugby AU teams were privately owned, either by individuals or groups of investors, the national and state unions would save a fuck load of money. The unions would actually be able to reinvest grassroots funds into the grassroots. At the moment you have a system where registration fees are going towards the wages of professional players, which is massive waste of the Unions money.
Additionally, the only reason Cattle is perceived as a problem is because we're constantly having to (unsuccessfully) play a game of "keeping up with the Kiwis", which wouldn't be a problem in a predominantly domestic structure.
I doubt there'd be a lot of money rattling around for a pro team in Western Sydney at the moment
We've already seen that there's investor interest for more professional rugby teams. And again, every other sport is able to find investors for expansion teams.
Are you trying to claim that Rugby administrators are in some way so catastrophically incompetent that they can't do what nearly every other sport in the country and the world can do? Even the US can find Australian investors for professional rugby teams.
This was the whole reason Super 12 worked to start with, extra TV markets,
We'd still get those extra TV markets from the post-season Champions comp. In fact we could get even more money from overseas markets because we could introduce extra countries into the post-domestic competition (Japan for example) without completely fucking over the format of the main competition, which you yourself pointed to as the problem that fucked the original Super Rugby.