google adsense account data

You can track them using channels. Create a channel and assign to the ad unit in adsense account. Once you assign them your reports show channel wise data which you can track.

There is no means to know the cost per each click for the publishers. If you are advertiser, you will get most of the information.

cost per click depend upon user's country , ad etc..

though by using channels , i don't think that we can know specifically which ad was clicked ..

we can know the page where clicked..