Walmart offers the Mohawk 5x8-Foot Home Avenue Stripe Indoor/Outdoor Nylon Rug for $49.99. Pad your order over $50 to bag free shipping. (Alternatively, opt for in-store pickup.) Excluding padding, that's the lowest total price we could find by $12, outside of the mentions below.
Close prices: Home Depot, Jet.com, and Hayneedle have it for $51.18 with free shipping.