I dont see any team throwing more than $10M at a goalie based on how the league has changed over the last 5 years. Bobs contract ($10) was signed 5 years ago. Vasi ($9.5) the same. Price was 7 years ago ($10.5).
Sorokin (8.25) was signed last summer. Helly (8.5) last October. Those are both definitely comparable goalies and locations. While Helly's contract is starting 1 year later then Shesh will (age wise, 31 Vs 30) Helly has 2 Vezinas.
The Rangers (and other top teams) recent runs and failures to win was not because of their goaltending. It was due to other gaps in their roster. Paying a goalie more and not addressing those other needs will doom this team to long term failure.
Tandems have become more prevalent and is still cheaper.
Think about it, you'd be paying an extra $7M to a goalie. That $7 could fund a top 6 winger, top pair Dman or hell a decent chunk of an entire 3rd line.
Arguably the Rangers first window closes in the next 2 years with the ages of the current core. While the cap will be going up in the future, I think the team is focusing on these next two years while building the foundation for the core 2.0 (Laff, Miller, Fox, Schneider, Perreault etc)