Walmart offers the Star Wars "Being Darth Vader" Comfy Throw for $11.39. (Amazon and Target charge the same price.) Opt for in-store pickup to dodge the $5.99 shipping fee. That's the lowest price we could find by $9. It measures 48" x 71" and is made from 100% polyester.

Update: The price has increased at Walmart, and Target now charges $5.99 for shipping. Amazon still offers it for $11.39 with free shipping for Prime members.