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Adsense is on the content network, search is the search network and they are completely separate things.
To get onto someones content site you pay as low as 1cent.
On the search network you could possibly pay 1cent but not likely - a nickle is closer to reality.
If so, the answer will depend on several issues:
the quality score for the site; the amount of comperition for bids on the keywords: and the currency bids are made in.
As a UK Advertiser, I can pay as little as £0.01 (that's about 2 cents) for some ads (albeit not many). I suspect that if I were bidding in US$ i could bid as low as $0.01.
I'm not sure what proportion gets paid to the publisher and what proportion is kept by Google.