The Google Adwords tool is displaying the search network CPC while Adsense is on the content network. That means that the CPC you're seeing is much lower than what you're seeing That and smart pricing is why the CPC is a lot different then the GAKT displays.
Try running your keywords through SpyFu.com, it's a neat tool that I like a lot better than the keyword tool when trying to get an idea of the CPC
No what I'm getting at is whatever keyword tool or service you use to determine the CPC it's showing the CPC for the search network. Adsense is the content network, thus it has a lower CPC. Every Adsense ebook/product I've seen uses the SEARCH network to determine the cost per click, but as an Adsense publisher you're receiving the content network payout. Anyone who's advertised on the content network will tell you that the clicks are substantially lower.
Yeah, but then again with the content network it's hard to tell exactly what keywords are being bid on, as every page will have quite a few of them. I think looking at the CPC for keywords should be taken with a grain of salt and be used more as a rough estimate for your niche as a whole compared to others and not for exact keywords.
Good point. A lot of times the keywords that Google thinks is relevant to your site is not the keywords you're optimizing them for. Ever try using the URL feature for your "optimized" pages in the GAKT? Even with EMDs sometimes the results are surprising.
Another thing to note is the fact that it's for Adwords and not Adsense, so Google scrapes money off the top by the time it gets to you (though I don't think it's enough to account for a HUGE difference in CPC). I actually haven't tried using the URL feature but I'll definitely have to try it out.