If CMC is good enough at ISU to get an offer from tOSU then he could possibly be a legendary coach at ISU where at tOSU he would be just another coach. At some point your legacy needs to be more important than money.
Remember, even Paul was an attractive option with other schools after regular seasons winning 6, 6, 5, 6. That's your tipping point right there. If Matt Campbell reaches 5 or 6 this year, he'll be on the list for coaching vacancies for sure.
The football world's perception is if you can win 6 at Iowa State, then you're good enough to move on to a place where you have better options for talent. I hope we have someone that finally removes that perception, we've been chipping away at it now with upset wins and greater facilities, but that is where we're at.