I have a hard time seeing any team offering him more than the Leafs would have. Why does Marner deserve more than Rantanen? Even if you look at non contending teams that could benefit from Marner, the should look at the Leafs as a cautionary tale by signing Tavares to a big deal and f***ing up their cap structure.
If Chicago signs Marner to play with Bedard for example it will almost certainly cost them more to sign Bedard.
If San Jose signs Marner to play with Cellibrini same thing.
Even the rumours with Vegas, if they offer Marner something excessive Eichler will cost that much more.
Only in Toronto do players get offered $13 + million with full NMC, max bonuses, endorsements, etc and think the team is insulting them.
I would be shocked if Marner ends up getting humbled and takes less than Rantanen somewhere and tries to spin it as low tax state, win cups, always respected that coach, or some other nonsense.