For those that do not already have a Wii System or if you know someone who wants one really badly, the box stores have been hording them away to coincide with the release of Mario Kart. I know that Circuit City, Best Buy and Toys R Us will have them based on online message boards.
An extra Wii Wheel will be $9.99 which is not a first week sale price, but the MSRP.
Here is a link to a picture of Sunday's Best Buy ad.
(NOTE: This is not my Flickr page)
And as a note to everyone, DON'T buy an extra wheel, they are just pointless wastes of money.
http://youtube.com/dukkysm64