Walmart offers the Nordicware 365 Indoor/Outdoor BBQ Grill Topper
, model no. 36518, for $13
for shipping. (Free site-to-store pickup is also available.) That's the lowest total price we could find by $7, although we saw it for a buck less a month ago. It measures approximately 14x16", and features a nonstick coating, small openings designed to prevent small food pieces from falling through, and more.