Often when I am using the Adwords Keyword tool I find keywords with a CPC of $0.05... I mean VERY often. Is this like base level when it comes to PPC or is this a possible error?

For example, with a few keywords I have targetted with a 0.05 CPC, I often find a PPC of 0.25 or more. Obviously, this is because my content is triggering other keywords, although it is centered around a 0.05 keyword.

I have found several keywords that have over 200,000 searches using the [exact] search parameter but have a CPC of $0.05. I plan on writing content to cover these keywords, but I am trying to figure the approximate value of these keywords.

0.05 leads me to believe there are no advertisers so IF someone were to advertise and use this keyword, it would cost them ~0.05. But since there is obviously no demand for these keywords and thus they aren't getting bids, other ads MUST be shown. How can I predict the value of ads with a CPC of $0.05?

Strange question I know, but I'm just trying to understand this a bit more.