Quoting: dannibalcorpse
It's less about the player and more about the retention. 3x$3M is a hugeee amount to retain and something we literally have never seen - there's only been 10 trades since retained salary became an option where a team retained $3M or more, and every single one of those was an expiring deal - no team has ever retained this high of a cap hit for more than the last 6 weeks of a season, and if Toronto is going to ask Boston to retain a literally unprecedented amount of cap hit (for a team in their division!) it's going to take an egregious overpay, in my opinion. It's not like the Bruins *need* to move Hall right now, regardless of whether or not they're going into a rebuild - something like 2/3 of their forward group is pending UFA this season, so they can go full tear-down without having to move out any cap.
If you're stripping the retention, though, then yeah, Hall isn't worth anywhere near this. He's a fine top 6 winger, he'd probably be an 85-90 point guy again on the Leafs, but I just can't see Boston eating that much cap for that long.
I'm not saying its realistic (quite the opposite actually - I made a similar AGM sending Hall to COL with the description "this is pretty unrealistic" -
https://www.capfriendly.com/forums/thread/632428/1), but there have been some large retention on trades over multiple years. Jeff Carter had around 2.6M retained for 1.5 years, so this is really just increasing the retention by 400k and adding 1 more year. Kessel was also 1.2M retained for 7 years, which is a bit different since its a lower $ spread over more years, but still
I only made the trade return big because of the retention, if were removing that then the value going back to Boston is probably cut in half