Of course, we have to assume Cousins plays near the same level he's been at in recent seasons and doesn't suffer a disastrous injury. Those are certainly worries in the back of his head, plus that of his agent, Mike McCartney. Per CBA rules on the franchise tag to which Cousins currently is shackled, the two sides now cannot negotiate until after the season.
But credit McCartney and Cousins for rebuffing Washington's last reported offer, which contained $53 million guaranteed, this spring. Sounds like a lot, eh? Washington president Bruce Allen seemed to think so when he leaked the contract info for anyone to hear, and in a vacuum, yes, it is.
Well, we now know that figure comes in $39 million less at signing than what Stafford just received — and that $53 million would have included the $24 million Cousins will earn this season. So ... yeah. You might believe Cousins is not as good as Stafford, and you might be right about that. But he's not that much inferior. No way.
Use whatever metric you want in determining QB greatness or value — passing yards, passer rating, games won, experience, playoff performance. It simply doesn't matter. Like in real estate, a quarterback's value is whatever the market dictates.