If you are thinking about a 12" box sub you'd be hard pressed to beat this deal:
http://us6.campaign-archive1.com/?u=7633d39bda9cfdce45d505f6f&id=596ba0d634&e=ebd74966e7
http://us6.campaign-archive1.com/?u=7633d39bda9cfdce45d505f6f&id=596ba0d634&e=ebd74966e7