You buy Mario Kart Wii, you get one plastic wheel. That should be enough. If you've got friends over who break into a rash when clutching a GameCube controller, though, I guess you could get another. How much is that going to cost you, though? If GameStop are on the money (see flyer above), you'll be looking at $US 15, which for a hollow piece of plastic is not merely taking the piss, it's buying the piss wholesale and reselling it for a profit. This is unconfirmed by Nintendo, and has since been taken down from GameStop's site, but the full flyer's after the jump regardless.
Wii Wheel Gets $14.99 Price Tag; Your Friends Aren't Worth it [Giz AU]