The Rams have tons of cap space in the next coupe of years (still have 50+ next year?), this is an extension, so basically 6 years $88 million, or roughly $16 million a year I'm told (not sure how that math works), it's also going to not be so hard to get out of in the future if need be. The Rams have locked up their top 3 receivers for a long time at reasonable deals. How could you possibly compare Cooks to Austin? One guy can't catch a cold and the other has had 3 straight 1k yard seasons. He may not be a top tier 1, but for the Rams I like what he brings. Getting paid about the same as Sammy Watkins who caught 35 balls last year and you saw how effective the Rams offense was with him.
This doesn't do shit to the AD situation. Fairly certain he's waiting for Mack to sign so he can have the biggest deal but we'll see.