The AAV on Darcy Kuemper's two-year extension is $4.5 million, per league source. Kuemper is in the last year of a deal that will pay him $2.1 million this season.
Hard to be unhappy with this deal. If Kuemper has a tough season, it's only two years - and if he plays well again, hard to see him signing something this cost-effective (and short term) rather than going to free agency at the end of the year.
Darcy Kuemper had his best season by a wide margin last year, but trended up the year prior as well. So two years is a reasonable risk, and $4.5M - more than he got on this current 'prove you can repeat' deal but less than the Holtby/Price range - is perfectly fine cost.
To add re: Kuemper: even if Antti Raanta has a stellar year as well, let's say you decide to keep him and give him two years, $5M AAV. If you think that a team tying up <$10M in starting-caliber goaltenders is a poor move, you're living in a fantasy world.