All depends how much they are willing to sacrifice talent for 3M in cap space. I think there might be a couple teams who could beat this deal with a equally cheaper contract and a later pick at the minimum.

What does montreal add?

Nothing. We take 3m in cap space.

Then Flames refuse, as stated above by another user your offer will be easily topped

Peca is fringe NHL player, Frolik's solid 3rd liner. There's a big value difference.

There are some teams that could, although its hard to say if there would be a lot of bidding for Frolik just with training camp opening and teams eager to find internal options, or waiting for their own UFAs to sign. I would think the Sens and Kings and Wings have the cap space and the assets to beat that offer but might not want to add a useful vet that could help spoil their chances at drafting Lafreniere. Maybe a team like the Devils would step up ...

I think its important to note that cap space value is an ever changing asset. 3M in July is not worth the same as 3M in October for example. 3M to Vancouver may not be worth the same as 3M to Colorado.

Simply stating they get 3M in cap space isn't enough. There needs to be a story behind it as to why CGY would trade a better but more expensive player for a worse but cheaper one.

Example is Cgy just signing Tkachuk to a 9.5M contract putting them over the cap. Given that they need cap space quickly they may just be willing to take the first cheapest offer given and not risk letting go down to the wire. Make no mistake about it, if they have the time to finesse it a little bit, they can more value for Frolik than Peca.