He could have definitely received more on the open market, with a lot of teams looking for Top-2 goalie help. At this stage of his career, not having to move is worth a lot and it allows Anaheim to carry a 3rd goalie in the event of injury with minimal cap repurcussions.
They could've paid him $3 Million for 3 years or something stupid like that. This is a good signing. If he gets hurt, they can call someone up.
Also 0.912 is not one of the worst backups in the league. It's not Vezina caliber, but it's not horrible either. Chad Johnson had an 0.884/0.872. Jake Allen was a 0.905. Garret Sparks was a 0.902. Adin Hill and Antti Raanta combined for a 0.903 or so. Etc. 0.912 is okay.