Google's Adwords keyword tool sometimes gives two different results for the same keyword, it's a lot more noticeable with super high CPC keywords. An example is the keyword "woodworking". Do a search on it and the phrase "woodworking tools" has a CPC of $39 plus. Now do a search for "woodworking tools" all by itself and the CPC drops to about $1.50. Now add "woodworking" to the search and it jumps back to $39 dollars again. Crosschecking it with spyfu.com shows the more believable $1.50 as the CPC. I'd suggest crosschecking those super high CPC keywords with spyfu or some other software before targeting those words.