This house isn't that impressive. I don't see it as extravagant based on his salary and past salaries.
At florida, (from a 2011 article) Contract is for $13,752,000 over five years. Average per year is $2,750,400. $500,000 buyout.
Doesn't include coaching shows, and product endorsements. Also, whatever he made at Auburn (he may have forfeited some of his buyout by coaching at Auburn), plus the equity in his existing home. Also his Auburn salary. Now he's being paid $3,000,000 per year at USC. Plus he got it at $425,000 under original asking price.
Yes, someday it may be hard to unload, but (as a realtor), I think he did OK here. Waterfront always adds more to the value.
Ever see Nick Saban's waterfront crib in Tuscaloosa?