The Mario Kart 8 Bundle is $329.99, you get the console, a controller, and a game plus the promotion for a free one.
Comparing it to it, this thing would be basically selling an all-new unique adapter and a cool figurine with fancy chips for $20. (Bet they're gonna do the free game deal again with Smash)
Don't really expect it to happen for that price.
It's totally possible, adapter+figurine is not really all that much, but I just don't they they'd do it. 329.99 For the same thing as the Mario Kart bundle, exept with a Pro Controller instead of Wii remote and obviously Smash instead of Mario Kart? I think I can totally see that happening.