The CPC values are provided by the Google AdWords keyword tool and they are, unfortunately, quite inaccurate. They should be treated as rough estimates more than anything. One of the issues is that there are actually many different things that factor into the cost per click on the advertiser's side, such as the quality score of their landing page and the position that they are bidding on.
Personally, I only use the CPC as an indicator of one out of three possible states:
It's been said that the Contextual Targeting Tool offers CPC estimates that are more precise and therefore better suited for estimating potential AdSense earnings. Unfortunately, there's no way for us to gather the CTT values in the vast numbers/speeds needed for SECockpit, so this is a feature we can't offer, at this time.