It's a bit complicated though.
Rayman: Raving Rabbids for the Wii just dropped to $18 on the used price
http://www.gamestop.com/Catalog/ProductDetails.aspx?product_id=63742
If you can get ahold of two of these (then the current sell would allow you to get another game for free) and then use an Edge card it should cost around $33.
Then trade in the two Raving Rabbids and pay $10 for Mario Kart Wii.
So $43 for MKWii and another used game for $18 for less.
Rayman: Raving Rabbids for the Wii just dropped to $18 on the used price
http://www.gamestop.com/Catalog/ProductDetails.aspx?product_id=63742
If you can get ahold of two of these (then the current sell would allow you to get another game for free) and then use an Edge card it should cost around $33.
Then trade in the two Raving Rabbids and pay $10 for Mario Kart Wii.
So $43 for MKWii and another used game for $18 for less.