Low salary is, of course, still relative. :)
For div 1, I would say something like 60-100k depending on the offense skill set that goes a long with it.
I would try to keep the salary as low as possible to achieve higher than average inside defense and decent offense which would need to be focused on outside shooting to keep the salary low.
However, taking Nachtmahrs explanations into consideration it does not seem to be possible without staying rather low on RB. That is close to what I'm currently running and I feel like it's worse or simply much more expensive than other strategies.