This is the kind of draft day deal you see pretty often in the NFL.

Based on current standings it translates to approximately pick 28 for 35 and 50. On paper I think this is good for the Leafs but depends on Seattle really wanting a certain prospect that they don't think will be available 5-10 picks later

As you said, it will depend on what the draft board looks like as their time to pick approaches, just like it does with every pick. If there's nobody on the board a team likes or there's someone another team really wants then a deal is possible. At the moment though there really isn't a discussion to be had about these kinds of deals.