Newegg.com also has Cougar Solution Black Steel Gaming ATX Mid Tower Computer Case for $39.99 - $20 rebate = $19.99. Shipping is free.
Note, both rebates are limit 1 per household and are valid 07/29/14 through 08/04/14.
Deal Editor's Note: The Fractal Design Core MicroATX Mid Tower Computer Case is now $5 less than the previous Front Page Deal. - Corwin