I don't think someone grasps the reasoning behind getting rid of Marleau. To answer your gauge question, you are not even in the same universe, forget same ball park (or in this case same rink).
The easiest way to explain the difference between Toffoli and Marleau is like this: You will have to pay to get Toffoli, but you also have to pay to get rid of Marleau.
In this case, nothing works. You're not giving up enough value for Toffoli, nor are you giving up enough value to get rid of Marleau's contract.
Trade is not realistic for both teams. Leafs need to dump Marleau for money reasons and it will cost them. They dont want old 13 goal Tyler for 4.6 mil.
People going all dramatic about this deal you do realize as painfully average Marleau was this season he was still more productive than Toffoli