stayonline.com is a less expensive source for the same type of cord, with a variety of lengths available:
Power cord NEMA 5-15 Male Plug to IEC 60320 C15 Female Connector.
The C15 female connector has the same pin array as a C13. However the C15 has a notch at the base. The C15 can be plugged into the C14 or C16 inlets while the C13 is limited to the C14 inlet.
http://www.stayonline.com/5-15-c15-power-cords.aspx
Will Strang, February 2009