I think hearing 21 mil probably trumps a lot of factors. If he's a good coach he'll be fine, it's power 5, it's the same region, and all the big jobs are closed. He can wait around in purgatory or he can try his hand at a major conference. Minnesota doesn't have to be the destination but it's obviously a step up.
I agree .. lets tier the BIG coaching jobs
Tier 1 - Michigan, OSU, PSU
Tier 2 - Wisconsin, Nebraska, MSU??
Tier 3 - Iowa, I would put Minnesota here
better job than Indiana, Purdue, Illinois, NW, Rutgers, Maryland -- MSU was in this group or at least with Tier 3 until Dantanio got on a run
I don't think a MAC coach at this time is going to get a Tier 1 job - maybe tier 2 if the timing is exactly right
Minnesota is a middle of the pack power 5 school - if you are a good coach you will maintain this level -- ie 7-9 wins and regular bowl games - you will likely not get fired at Minnesota for quite some time with this level of success. In this respect you might be better off at Minnesota than at Nebraska at least as far as longevity is concerned. Consistent 8-9 win seasons at Nebraska will get you fired - probably not at Minnesota. If you are a great coach Minnesota will move up a tier and you now will have your name in the hat for some bigger time power 5 jobs. If you are a great, great coach you get Minnesota into the top 10 - if you do that once at MInnesota every big program comes calling and Minnesota ponies up big. If you do that at Nebraska you get a slap on the back and told to do it again and again.
He, by some reports, is getting paid close to what Riley is with much lower expectations.