Well, what exactly do you want? Do you want to find out how much do you have to pay/click if you start a campaign in Adwords or just to find out what's the value of the clicks -if you are lucky enough? There are 2 different values, truth be told.
First of all, the CPC listed in Adwords is not equal with the CPC in Adsense. It's just the ~value of the click and it's more helpful for the advertisers and not for the publishers.
That's because the CPC in Adsense depends of a lot of factors. From my experience, I can tell that the CPC in Adsense depends of:
- cookies in the viewer's browser;
- region;
- period of the year and even of the month;
- whether or not the account of the publisher has been smartpriced;
- and so on...
Hope it helps.