The money argument for the Zibanejad/Brassard swap never passed the smell test.
If you wanted to save a couple million there was plenty of other ways to do it besides trading your young raw top 2 center.
It's just BS to excuse the awful pro scouting that led Dorion to believe Brassard was the #1 center they were missing.
It isn't so much money related to what Zib and Brassard cost. Although that is one aspect of it that Brassard was cost controlled, and Zibanejad could have ended up costing a lot more in years 2 and 3 of the deal.
It's that they had a window to win that was caused by an unwillingness to spend money. A normal team would look at the roster they had and be more patient because prior to Karl's injury (which they wouldn't have predicted), they would have projected that Karlsson and Stone would be impact players for another decade. So if Zibanejad is going to take another 2-3 years to get there, that's not a big deal.
The thing is that their window was based around Karlsson's contract (because of money), so it was more like they had 3 or so years left to win and wouldn't benefit from Zibanejad putting it together later on anyways. So even if the trade itself didn't save a substantial amount of money (it saved some), it was motivated by money and the effects of the budget in a more macro sense.
That isn't me absolving the pro scouting of Brassard, who really wasn't as consistent or good for Ottawa as he was advertised as being in New York. I'm just pointing out that when you accept that the team had to be working under the notion that their window was based around Karlsson's contract (because of the budget not guaranteeing they could keep everybody), and work backwards from there, trades like Brassard, Phaneuf, and Duchene aren't excusable, but they make a lot more sense.
You can't judge those trades under the scope of what a normal team would do to maximize their position. Normal teams or teams fortunate enough to spend beyond what normal teams do are the ones who took advantage of Ottawa having to make those kind of trades to maximize their position. The Rangers got Zibanejad because of the structure of Brassard's contract. The Leafs got out of Phaneuf for nothing by taking a bunch of short-term money (and later Zaitsev). Colorado got a haul for Duchene because having 2 years left to win and minimal opportunities to add a legit 1C gave Dorion tunnel vision.