buckworks - 6:19 pm on Nov 26, 2011 (gmt 0)
Here's one more thought in response to the OP.
As long as they have good relevance, there's no reason to avoid keywords that have high competition but low search. Just be realistic about how much performance to expect, and stay out of bidding wars.
Set your bids according to what will be cost-effective for your business, and let those keywords deliver whatever they deliver while you work on other things.