I'll add 2 things -
1) If Fitz finds himself hosting Saturday Night Live, I'm going to guess that his endorsement income is going to skyrocket. The difference between Fitz and Peyton is that Peyton Manning transcends sports. My grandmother knew who Peyton Manning was. Fitz embodies sports, but doesn't transcend them in the same way.
2) Brian Billick is listed at $25-40K for a keynote address by the National Speakers Bureau, as a guy who authored one book, was prominently featured in another, currently takes the airwaves every week as an announcer, and whose job it was to motivate a group of players week after week. And he won a Super Bowl.
I think that unless it's a Fantasy Football Players' Convention, Fitz is getting $20K to speak for 25 minutes.