You're correct, I think it is $6M
The buyout other teams pay for taking your coach is always way less than you pay your coach for letting him go
This is because it's about protecting the head coach's pay. If another team hires him, they're paying him. The university isn't out much from losing their coach - the buyout to the university basically pays for conducting a national search and buying out the contracts of assistant coaches that the outgoing coach doesn't take with him and the incoming coach doesn't want to keep.