I think that while we have some good talent in this league, the sport isn't big enough in the league to turn players into "Household names" like a lot of major sports do.
Because of this, even if it was financially viable to do trading in the league, I don't think anyone but the die-hard fans would care.
Part of the enjoyment of "trading" is the impact it has on the sport and how the fanbase react. While we may see someone like Shawn Redhage being traded to Melbourne as a big deal and a massive impact on Perth; if you try to advertise that to the general public, you're not going to get a reaction unless people in general know who he is.
If you get the Financial backing to make trading viable, then good. But you honestly need the NBL to become a top tier competition again before trading will offer entertainment level impact as well as league impact.