I did the same thing and read through Campbell's contract last night. The $9.3MM buyout does two things. First, it makes the number of schools that could potentially hire him smaller. As others have said it would be no obstacle for some programs, but there aren't more than about 15 of those. Second, in a worst case scenario we would be looking for a new coach and could all of a sudden offer in the $3-4.5MM per year range because of the money in the bank. While obviously not ideal, we would at least have a much wider pool of candidates (plus more money for assistants).
The more interesting thing to me is how will the current contract structure effect negotiations on a new one in the next year or two. Lets say after this season we wanted to give coach a new $3.5MM per year deal through 2023. Would coach be willing to keep the same buyout structure (which is much higher than the norm nationally)? Because I can't see a scenario where we'd be willing to give a significant raise and lessen the buyout. Maybe they'd compromise on something like $2MM × the number of years remaining on the contract or a flat amount of something like $10MM (best for ISU because it doesn't reduce over time).
Anyway, all the thinking I'm going to do about that until the off-season. Now for the biggest football game in my time as a fan (since the early 90s).