Utah, has Keller at $7.15M for 4 more years. He is the top paid player. I'm not going to speak on behalf of Utah fans, but I very much doubt they'll give Marner $12M, much less trade any asset for him. (never mind, actually Sergachev is $8.5M now, still way under $12M).
NYI, that has 900K cap space. Lou as the King. Marner is not a Lou player.
SJ. They're rebuilding. Explain why they need Marner @ $12M?
You just saw Nashville give Stamkos 8M per for 4 years, and he's inferior to what Marner is at this stage of their careers. Like not even close. Stamkos puts up points, yes, but he's not in the same class of player anymore.
Point of rebuilding is to get talent on the roster, and to become better. You can also do that via UFA. The market is simply not comparable to what the perceived worth of these players is to their own respective teams at this moment, or as an RFA.
Tavares, Panarin, Gaudreau... These top tier free agents simply get paid. Gaudreau probably would've gotten more from other teams, but he chose Columbus. If Draisaitl would actually hit free agency, there would be a team offering him 15M. That's a fact. Mikko Rantanen? Upwards of 13M. That's just how this stuff works.
And no, I'm not a Leafs fan. Quite the opposite really. Their own cap structure is frankly stupid, and a combination of MANY errors. But that's not really relevant to what their star players could get on the open market.