Not really related because it's a different company, but wasn't DuckTales like $5 more expensive on disc?
Ducktales was a single game. I'm talking about when it is more then a standalone title. Low price for two games that people would not have bought otherwise because they didn't want to waste $30 for digital titles. Physical tends to appeal to people a lot more then digital. Hence the reason companies Bethesda like to release editions of their games with all the DLC on a seperate disc (Fallout, TES, Dishonored, and I bet you money when all the Wolfenstien DLC is out there will be one there too). You aren't paying the the $30-$40 you would regularly for all the DLC on top of the $50 for the base game. People who haven't bought the game will see a deal and jump on it.
Nintendo would be foolish to charge $40 for this. $30 would give people little incentive to buy it if they didn't before aside from having a physical copy. $25 would probably be the best priced.