TigerDirect has New Super Mario Bros. Wii U for $34.99:
http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=7440447&CatId=7663
Shipping is about $4, and tax applies for those states affected, but even with both, that's the cheapest I've seen the game.
I've already...
I took advantage of this sale, but I wanted to provide follow up because my order of three games arrived with one crushed because of the way they packed it and the other two have obviously been sitting in the sun somewhere because the sides have that lovely sun baked tint. I took a chance...
In case anyone is interested, Newegg has Conduit 2 for $13.99 total (except where tax is charged):
http://www.newegg.com/Product/Product.aspx?Item=N82E16878142070