Long keyword phrases more expensive than the shorter version

Can I get cheaper CPCs by using the shorter version (broad match)

[namniboose]

I have been including long keyword phrases thinking they would be cheaper than shorter keyword phrases, but I am noticing that some keywords are actually more expensive (for obvious reasons).

So if I eliminate longer keyword phrases, won't my ad still come up for that keyword phrase if I bid on shorter keyword phrases (broad match)? and at a cheaper CPC than if I bid on longer keyword phrases.

Or is there something I'm missing?

[edited by: engine at 8:24 am (utc) on Aug. 7, 2008]
[edit reason] no specific terms, thanks [/edit]

[SanDiego Art]

You are missing all the OTHER keywords that will be matched to the broad term. It would seem that those clicks would be eating away at budget, while you are just trying to get a specific term. It would seem by bidding on just the term you want, vs. anything Google determines relevant would be more cost effective?

If I sell Red Nike Shoes, I would rather pay more for that term, then to be Broad (or Phrase) matched to shoes, red shoes, or nike shoes. Because I don't sell Green Nikes, or Red Adidas. Even though the shorter (less targeted) terms "MIGHT" be cheaper... They are usually way less efficient (and therefore cheaper).