According to hockey-reference, league average goaltending this year was a .915sv%
http://www.hockey-reference.com/leagues/stats.html
Lundqvist finished this season at .920. Let's do some extrapolating...
Lundqvist faced 1944 shots this season allowing 156 goals for that .920 sv%. A replacement level goalie (ie. league average) operating at a .915sv% would have allowed 165 goals. 9 more. Very basic and unproven WAR calculations suggest that 6 goals created or taken away is a win. So, Hank's WAR this season was 1.5. Take away three points in the standings, and the Rangers are WC1, and faceoff with the Panthers tonight.
However... if rather than taking into account all game time (PP, PK, 3v3 OT) and just look at 5v5 play [where majority of the game is played and majority of the analysis takes place], league average goaltending was a .925 sv%.
Lundqvist recorded a career best .937 sv% at 5v5 play this season facing 1532 shots and allowing 97 goals. A league average 5v5 goalie with that workload would have allowed 115 goals, 18 more. Lundqvist's WAR at 5v5 was 3. Take 3 wins away from the Rangers, and they don't make the playoffs.
Now, the reason for this post is because I saw a lot of talking in the GDT last night about how it is folly to build a team around the goalie... Part of me agrees and disagrees with this sentiment. It's easy to say, well, if the Rangers didn't have Lundqvist, they'd have better than just league average goaltending... but is that true? You have to figure that there are 15 teams in the league without league average goaltending... how are they all fairing? Hell, there are some teams in the league with league average goaltending that aren't fairing too well, either.
Of course there is the opportunity cost. The $4m you save on goalies could be used elsewhere in the ranks, improving the offense or the defense... but, this Rangers team, for all their faults, finished 7th in the league in goal scoring, and STILL if you replace Lundqvist with league average goaltending, they don't make the playoffs.
So, think about it. How much better can the offense get? How much worse can the goaltending get? Seems to me, there's a much bigger hole going down than there is opportunity going up.