Don't forget USPS flat rate shipping:
http://www.usps.com/rates/priority-mail-rates.htm





Priority Mail Flat Rate Boxes




Any mailable item sent in a Priority Mail Flat Rate box provided by the Postal Service, regardless of weight (up to a 70-pound maximum) or destination. Flat Rate Boxes are available in several different size and shape options.

Priority Mail Large Flat Rate Box
Priority Mail Large Flat Rate Box is 12" x 12" x 5.5" and is 50% larger than other Flat Rate boxes.