You honestly wouldn't have to pay that much. That contract is atrocious.

I propose Backes straight up for Hagelin with 2,000,000 per year retained. This favors the Pens slightly in years 1 and 2 but, Boston benefits in years 3 and 4 when Hagelin is off the books Boston isn't paying a 35 or 36 year old 6,000,000 per year.

Honestly, Boston should pay you for taking on his contract.

Backes has a NMC and just singed last year, why would he agree to a trade when he admitted transitioning to a new city was hard for him.

Because he only has a No Movement Clause not a No Trade Clause. A NMC only protects from being put on waivers to be sent down to the farm team.

No, a NMC means a player can't be put on waivers/sent down or traded without their permission. Basically a NMC puts the player in the driver seat. I always look at it like this...

NMC = you can't move the player without permission, whether trade or waivers it doesn't matter
NTC = you can't trade a player unless player waives, but you can send them to the minors/waivers.