Just a quick heads-up, the Wii U GameCube controller adapter is in stock at GameStop online for $109.97, which means that you'll have to buy the Smash Bros. bundle to get it. It includes the Wii U edition of the game, as well as a GameCube controller and the adapter itself.
To price it all out, the game is $60, the adapter is $20 (but sold out everywhere), and the controller is $30 -- so you're not saving anything, but if you're desperate for that adapter you could always sell off the other bits yourself.
Wii U GameCube Adapter [GameStop]
via destructoid http://www.destructoid.com/wii-u-gamecube-adapter-is-in-stock-at-gamestop-in-bundle-form-285507.phtml