1 million is a good minimum for this salary level to force you to spend money on your bench. There are some good players between $1 mil and $3.5 mil. Chuck Hayes, Marcin Gortat, Greg Oden, Danny Fortson, Chris Gatling, Patrick Ewing, Roy Tarpley. Magic, Kirilenko.
I think to round out the socialist theme you need to have both a minimum and a maximum. No player below $1 mil and no player above $7 mil, or something like that.