The difference between Binnington's situation and all the others?
-- Copley is clearly a backup to Holtby.
-- Delia will still be a backup to Crawford.
-- Stalock is clearly a backup to Dubnyk.
-- DeSmith will still be a backup to Martin.
-- Binnington is not going to be the backup to Allen. The way things are going, there's a high probability he earns the #1 spot to start next season.
That's why I'd be shocked if he settled for $1M and change. With every start that he looks solid and confident in net, his price tag for next season just ticks up a little more.
I believe you meant Murray here, as the only goaltender Martins I'm aware of are Martin Jones and Spencer Martin (Avs AHL goalie).
I'll agree with you that Binny gets more than the 800k-1.25m over 3 years each backup signing has received so far, but he's got considerably less of a resume than most other backups turned starters had (off the top of my head, that list includes):
Darling 75 NHL games played, signed for 4x4.15m in May 2017
Allen 99 NHL games played, signed for 4x4.35 in July 2016
Raanta 64 NHL games played, signed for 2x1 in July 2016 (behind Lundqvist)
Andersen 125 NHL games played, signed for 5x5 in June 2016
Gibson 26 NHL games played, signed for 3x2.3 in Sept 2015 (tandem Anderson)
Jones 34 NHL games played, signed for 3x3 in July 2015
Vasilevskyi 40 NHL games played, signed for 3x3.5 in July of 2016 (tandem Bishop)
Grubauer 101 NHL games played, signed for 3x3.3 (tandem Varlamov)
Of these backups turned starters, only Vasilevskyi, Allen and Gibson assumed starter roles on their own teams. The others all were traded to other teams when it was clear there was already a starter ahead of them.
When you consider this list, as opposed to RFA backups signing deals, the Koskinen extension doesn't look as egregious (though he's unproven relative to this list). Binnington's agent will likely push for something closer to the 3-4m over 3 years, I'd like to think DA would try to get something along the lines of Gibson's first deal at 3x2.3m in an effort to get a bigger sample size before committing long term.
Though if his play regresses and he isn't viewed as the de facto #1 for next year, I can see the 1.1-1.4m over 2-3 years I'd predicted previously if he remains an RFA being closer to the mark than a 3x3-4m contract.