You fail to realize that the habs and the bruins were in complete different positions. One was rebuilding and the other was in win-now mode. Obviously, the team in win-now mode will try to upgrade every position as much as possible. The team rebuilding or just exiting their rebuild isn't going to do that, especially if its just for short term help and will cost good assets.
You keep talking about Dvorak and mediocrity, but if you really wanted the habs to make the playoffs and go far, you wouldn't be talking about Dvorak, you would be talking about upgrading on Newhook. You know that player who has been in the top 6 all season, but has even less pts than Dvorak.
If the Habs stay in the hunt at the deadline, I don't think the Habs will be buyers or sellers.
They can't sell because that would be pulling the rug out from underneath the team and shitting over their developments as a team. That would be a good way for management to lose credibility amongst the leaders on the ice, and to destroy the morale of the room. This all would run opposite to the culture they are trying to foster.
They can't buy because the vision can't be lost which is to continue the development path with the youth. The youthful core has brought you this far, and you leave it in their hands and let them grow from this playoff chase.
In this scenario, I can see the Habs getting reinforcements around the edges, but that's as far as they ought to go this year in terms of adding.
However, if they end up around the deadline in free fall, then all bets are off. You can look the players in the eye and tell them you had the opportunity and it didn't work. The players won't like it but deep down, they would know it was fair.
By the way, in the seller role, I'm not advocating anything more than making decisions on veterans and particularly the ones with expiring contracts such as savard, armia, and Evans one way or the other.