It's not that much of a savings. The Sabres qualified Foligno & if he decides to go thru arbitration I'm guessing he'll be around 3.5-4m per season. Minnesota is only gonna see 1-1.5m savings.
I don't see how Foligno is going to see $3.5-4 m, even with arbitration. He made @2.25m and his scoring hasn't really improved since his previous contract ... I think he'll get $2.5-3m max. He might even get paid less then his previous contract as that "potential factor" has faded. You'll pay a guy on the upswing some more in hopes that he keeps going up. Foligno has already leveled off.
I think it's a pretty darn even deal, when you consider the cap space the Wild needed, the age of Pominville, and the pick. Scandella is the best in the trade, but Min got younger and even if Ennis can't keep up in the west, he can put up decent numbers and there's plenty of teams in the East that can use him. If he can stay health long enough to put up some points like he has in the past, he can be moved to add to the value of the trade. putting the Wild over the top.
Foligno is 25, and big. Even if he's just a 3rd or 4th line guy he's still can grow WITH the core (Niederreiter, Granlund, Zucker, Coyle, Spurgeon, and Brodin) of the Wild team, and Ennis at 27 fits in there too. Unless you expect to win this year, Pominville was very expendable. Especially if his numbers drop off. Either way Ennis' career SHOULD be longer, and potentially as productive.