AutoAnything is having a year-end 12% off sale on Corsa Sport and Touring Exhaust. seems to be the cheapest online at the moment, I believe the sale ends 12/29.
http://www.autoanything.com/exhausts-mufflers/61A2937A0A0.aspx
http://www.autoanything.com/exhausts-mufflers/61A2937A0A0.aspx