What is with everyone saying about the controller attachments costing too much?
This is Nintendo, they'll most likely bundle them in with the game that utilizes them. StarFox64 had the rumble pack, Donkey Kong 64 the graphic expansion unit, Zelda: Four Swords Adventure had the GBA/GCN Linkup Cable, and Pokemon the wireless link adapter.
Why would this change now?
Also, third-party devs/pubs might create their own addons to the primary "controller", no? Like Namco might include a racing wheel column in a Ridge Racer game, etc.