Official Crysis and Warhead sales actually was announced

[ssj12]

Page 10: http://www.zuse.hessen.de/mm/Konrad_Zuse_Kongress_Yerli_Final.pdf

3 million sold, and 2 million. So by now the number had to have increased thanks to the Steam sales. I'd say 4 million crysis and 3 million for warhead easily.