Hopefully Autoweek has the right numbers for horsepower (300) otherwise it is quite an expensive dress up job. It's still probably expensive even with 300 HP. I guess for $15000 and a run limited to 500 a year they think people will buy them as collector's items or something.
2012 Focus specs: http://media.ford.com/images/10031/2012_Focus_Specs.pdf
2013 Focus specs: http://media.ford.com/images/10031/2013_Focus_Specs.pdf
2013 Focus ST specs: http://media.ford.com/images/10031/2013_FocusST_Specs.pdf