<http://schema.org/description>
"According to various sources, Microsoft has confirmed that anyone who purchases a Windows 7 PC after June 2nd can then upgrade to Windows 8 for a mere $15 (valid through January 31th, ..."^^<http://www.w3.org/2001/XMLSchema#string>
<http://thenextweb.com/microsoft/2012/05/31/it-will-set-you-back-15-to-upgrade-to-windows-8/>