G can be very expensive, but not always. I know this....I certainly won't use them anymore for advertising my usability analysis. Even if I convert 1 out of 30, at $2 or more per click, I'm in the hole.
Yes and no. I personally like the EXTREMELY targeted keyword phrases (4 words or more) that you're sure someone types in to make a final purchase. Those arent so expensive. The expensive part is having a big enough budget to make sure your ad is showing most of the day....that is a killer...