Beleive it or not, 5mil is a discount. Kesler could have went for 5.75mil for sure on the open market, even 6mil.
Lets look at a few recent center position signings..
Stajan - 3.5mil
Antropov - 4mil
Vermette - 3.75mil
Kessel - 5.4mil
For what Kesler brings, 5mil is a great deal. He's on pace for 76 points, it's not likely he's going to sign a cheap donkey deal and if he does it won't be for 6 years. This is very fair for both sides and I'm glad they got a deal done.