I've said time and time again, the only city in Australia that needs two NBL teams is Melbourne. Note I said 'needs'. The only other city that I believe could sustain two NBL teams aside from Melbourne is Sydney. The idea of a West Sydney franchise was one of the better ideas the NBL have had for a while, it just wasn't executed properly.
Melbourne need another franchise purely because of the divide between the overall basketball playing/coaching population and the Tigers as a result of the Melbourne Tigers junior program.
Sydney could sustain another NBL team based in West Sydney purely because of the geographical divide existing between the CBD and the Greater Western area.
There just doesn't seem to be a great deal of need to divide the supporter base of a city, particularly when these Australian cities aren't exactly falling over themselves to support their current NBL teams. If Perth we're to build themselves up into a position where every single game at Perth Arena was a sellout, and they've got 10,000 members on board each and every year, along with an extensive waiting list, then maybe, MAYBE, it would be worthwhile. But in contrast, look at the NBA. You've only got two cities with two teams, LA and New York, and even New York only just got their second team last year. And those cities have populations of 4 and 8 million respectively. Chicago has a population of nearly 3 million, and the Bulls sellout 20,000 seats to 41 games per year, yet the city of Chicago doesn't see a need to have a second NBA team. That's because the entire city supports the Bulls. Whilst the games sellout, and its difficult to get tickets, other revenue streams open up such as local TV and radio broadcasting.
The immediate expansion focus for the NBL must be a new Brisbane franchise, and another Melbourne franchise. Once those two are in place, then they can entertain the idea of further expansion.