They can create a ton more room by cutting the vets that should be cut, and resigning the cheap ERFAs to fill out the bottom of the roster, so yes the Seahawks have more than $50M dollars to spend as it pertains to re-signing their own and upcoming UFAs.
Playing with the Calculator -->
I cut Wagner, Myers, Collier, Carson, Hyder, and Blair.
Signed cheap ERFAs: Neal, Mone, John Reid, Hart, Muse, Warrior, Rhattigan, Ursua, Heslop, Webb, Shepley.
Retained RFA Phil Haynes on the original round tender.
Also signed Geno Smith to a vet min deal as a place holder.
Giving the Seahawks 50/51 players on the roster and $70.4M in cap space.
Wagner is key, $16.6M in cap space alone can be created for 2022 by cutting him.
The salary cap has turned into a bit of a joke though. Teams have been signing guys with voidable years to keep the cap hits down, Seahawks included last off-season. Which the league should get rid of this practice if they actually care about competitive balance.
So the Seahawks can spend a whole lot more if they really want to. $50M could turn into as much as $250M if they want to stretch voidable years to their max. No team would, just trying to point out if a team really wanted to they could kick that can down the road. Ultimately there is more flexibility than just $50M to spend and that's it, it's not that rigid.
That is not even getting into restructures that can create cap space out of thin air at any given time when needed.