If you think Lundqvist is better than Price, Holtby, and Schneider in 2016-17 I don't know what to tell you. Better career, easily. Not now.
He's better than Holtby, who benefits from a very strong team in front of him. Price I'll give you though he needs to stay healthy and show his Vezina season wasn't a fluke (not that I think he'll drop down to being bad or something, he's a great goalie). Schneider is also close, currently.
That's also 3 goalies and not 4-5
Lundqvist's play hasn't dropped yet, I don't know why we need to act like he's currently an issue. I do agree you have to worry how things will work out when his play finally does take a definitive dive and what the cap space will be like, but at that point I'm also far more worried about finding a good replacement. Cap space and an average goalie doesn't do a ton to help this team.
It's fine to worry about how the Rangers will manage their cap space but realistically the choices they have made in other areas are far more detrimental to the team now and in the future than the money invested in Lundqvist.