You're assuming Wilson could have been had for $500K less. A 16th overall that's played full-time in the NHL since he was 19, coming off a season where he took huge steps forward on the forecheck and PK, and is already regarded as one of the league's toughest guys and savvy at drawing penalties? That guy gets paid, Hive.
You can claim all you want that he could have been had for 25% less, but you have no way of knowing that. Wilson's agent had Orlov as a recent comp with a lower draft position, less NHL experience, and less accomplished, getting $2m. It's not apples-to-apples, but it didn't have to be. Wilson played well last year. That he hadn't gelled offensively yet, at 21, wasn't that big a deal. Why? The comp and...
Simmonds was their best player in that game. Wilson knew he was busted right after the hit, yet kept his head enough to take their best player off with him for 5 of the 7 minutes left in a playoff game with a 1-goal lead.
He's no dummy, shows versatility, size, speed, extremely rare physicality, durability, defensive and fighting acumen... Just coming off his ELC, that guy gets paid. Period.