Edit: Deal is DEAD -- no more copies available.
An eBay seller is selling brand new, sealed Wii-U Mario Kart 8 bundles for only $305 with Free shipping.
By far, this is the cheapest I've seen the bundle on sale. The retail price at online & brick-and-mortar stores is $329.99. Even though most online stores offer free shipping, they also charge taxes which come out to be a total of +$350, depending on your state.
I've been shopping around for a Wii-U since the new Mario Kart 8 came out, and for this price with everything the bundle offers, $305 felt like a steal.