That isn't exactly basketball either.
Looks more like $40M from TV broadcast and $8M from CFP contract money came there way in a recent year along with $40M in donations. So $84M right there. Yes TV broadcast includes all B12 sports (football, bb, and others) I am sure most of the broadcast money is due to football due to other members of the conference...
That doesn't even detail how much in ticket sales, etc are split between football and bb. But I'm still not convinced that they make much more from BB than football.