I don't know of any college coach, of any standing, who has a prohibitively large buy out provision if they leave for another job. Franklin's, for example, is relative chicken feed. Do you? Obviously, we don't yet know exactly what the specifics may be in Tucker's new contract - should it go through.
But, yes, if there is a huge buy out clause - attached to the coach going elsewhere - that could impede the coach from moving.
Even when they did exist, they were usually bargained down to a much lower number - because what is the option for the school? To have a coach leading the team who doesn't want to be there? It just isn't a practical solution.
For what it is worth, Penn State did get around $6 million when Bill OBrien went to the Texans. But buy outs of that magnitude are very rare, if not non-existent these days.