Yugster offers the Scosche sportSHIELD Case for iPad mini in six colors for free with $5 for shipping. (JayzElectronics2011 via eBay offers it in Green/Gray for the same price.) That's the lowest total price we could find by a buck. It features integrated notches for use with the Apple Smart Cover (not included) and a shock-resistant textured rubber exterior.
Note: The countdown timer on the product page does not reflect an actual expiration time and resets daily.