If SAF is going to bench Ronaldo, he might as well sell him. He'll do the team no good with the wrong attitude.
He should take the best deal if he can't normally figure something out with Ronaldo. Ronaldo is either commited or he's out. That's the only way I see it. They need to have a meeting and sort out their differences.
If Ronaldo wants to leave after that, then Man U needs to take the best deal. From what it seems, Man U can get a crazy deal out of this. They can get around 40 million plus 1-2 quality players from Real Madrid.