As one of its daily deals, Groupon offers the K'Nex Nintendo Mario Circuit Ultimate Building Set
, model no. 38501, for $39.99
with free shipping
. That's $10 under our December mention and the lowest total price we could find by $28. The set includes 50 pieces of track that combine to form a course from the Mario Kart Wii video game, karts driven by Mario and Toad, and more. Deal ends May 18.