Yes, he is. I appreciate the optimism of the $15-25M crowd, and I would love for them to be right.
But when you see what's being paid to mid-range veteran starters this year and overlay historical salary increases ratioed to cap increases it would not surprise me to see Geno offered $40M+/year with multiple years guaranteed.
I think he has to get at least the equivalent of a Ryan Tannehill if he finishes the season at a similar level to where he is now, which isn't exactly cheap, but not a ridiculous deal either. Tannehill isn't considered a prime Brady or Rodgers but as we have seen with Tennessee's rookie experiment, he's a definite upgrade over most QBs in the league.
Even if you think Geno is a 'system' QB, he's at least an effective, efficient, Tannehill level system QB.
We do have a few things working in our favor that might keep the cost down.
1.) Geno seems to enjoy playing for this team, for this coach, and in this system. That's not nothing even though some people think it is. There are still players who take 'hometown deals'. I get it, Geno is probably going to sign his last big contract but if he's listening to more people than just his agent, he also knows that means he's signing on for the last years of his football playing career.
2.) Geno IS older. That might make some teams hesitant to make any offer more than a couple of years. Thus, if we're willing to do that, we might be able to take some of the yearly amount down by offering more years.
3.) The Russell Wilson effect. This was the biggest splash contract extension in recent NFL history, and it is going down like the Hindenburg. NFL teams have been overpaying like crazy for any QB play that can be described as mediocre or better and the QB is perhaps the most overvalued position in the entire NFL, but the Russ-drama has been seen all over the NFL.
QBs have been overpaid because no team wants to be the one that let their 'HOF franchise QB' get away because they were stingy, but could the sentiment be shifting to no team wants to be the next Denver Broncos? Maybe. Green Bay is in the middle of seeing the exact same issue happen very, very publicly with A-a-ron.
QBs are the most important individual player on a football team but as Denver and Green Bay is learning (and Seattle hopefully learned), if you can't afford to put other weapons around your QB... you are going to be screwed.
That said, NFL Front Offices are all loathe to be the first one to jump on a new paradigm and all it takes is one Exec who still believes they are just a 'QB away' to drive the bidding war.
Seattle should try to keep Geno at any reasonable cost (and Ryan Tannehill's contract seems reasonable to me, adjusted for the new cap rates) but the QB is still only the most important player on one phase of a three-phase game.