I would be surprised if Kreider didn't get 7x7 as a UFA if he went to the highest bidder. He is a good all-around player nowadays. Good on the forecheck. Good at getting to lose pucks, and remarkably improved as to what to do with those lose pucks. Distributes them well in the attacking zone which is important. Of course he has the speed and is a danger of the rush.
GMs will value that, he is a sure-fire contributor. And as soon as you start to go below 7m you are not even getting that. Its not a matter of what he is "worth", its just a simple pragmatic decision by GMs for teams that has money to spend. Often these GMs job is on the line in the near future, and odds are that they won't be around for the tail-end of these contracts.
But if he want to stay for like the Charlie Coyle contract, 5.25m for 6 years, or a little more, I am sure he would be a good keep.