Well, I suppose you can't blame the man for wanting to cash in. But my goodness...
My concern with Dubnyk and this whole "savior" mentality is, well... yes, he played in front of a desperate team fighting for it's playoff hopes, but lets not forget that a good majority of starters (and even backup) tenders would look absolutely spectacular to a management group and fan base who'd witnessed the body of work Kuemper and Backstrom orchestrated together.
When you're that desperate for a run of the mill save, when that's the difference between winning and losing... any goalie that can come in and do the job he's supposed to do will, for a short time, appear like a Lundqvist reincarnate. For nearly two months the media picked apart Keumper's inability to stay mentally strong in a game. The contrast was ready to be set, all we needed was a goalie to do his job.
And while, yes, it's not to say Dubnyk didn't make some spectacular saves, I (to be frank) didn't see star caliber play coming from him on a consistent basis. And, again, it's not to say he isn't capable of such play, but rather, that it hasn't been proven consistently (yet... perhaps). The sentiment of whether Dubnyk's 3.5 months of play with us is indicative of future performances is a very real concern. Player's playing for a contract is a very real concern.
Call me a jerk, or what have you, but these contract negotiations smell an awful lot like a guy who realizes he just did something spectacular (partly thanks to him no doubt, and partly thanks to a great defensive team), and wants to reap as much as he can from it because he knows it may not happen again (I know this is a little facetious, so go easy on me haha). Sure, I'd be OK with giving him 5Mpy if it was for one year; Or 4.5Mpy for two years; 4Mpy for 3 years, and so on.
He just hasn't proven enough to command both money AND term. If I'm Fletcher, I meet Dubnyk on one or the other, committing to both would be cap seppuku (as already stated).