Targeting Valuable, Poorly Represented Keywords

I have been looking at the Google CPC Est Avg and the Overture top bids for various keyword phrases.

Not surprisingly, some phrases in my service offering domain seem to be more expensive relative to other relevant keyword phrase choices.

For example,

orange rabits $3.28 GG $3.75 OVT
purple rabits $0.75 GG $1.05 OVT

Given both keyword phrases have relatively weak sites with minimual value content that I can surpass, should I be targeting the high bid PPC, low bid PPC, or not care?

I haven't decided if I intend to display any kind of PPC ads like AdSense or not. I am not seeking to buy any PPC advertising just yet either. It's more a question of targeting development time in the most effective manner possible.

Thanks.

I wouldn't chase the top10%

You can get more and better converting traffic targeting the 40-90% range and the longtail keywords.

You have a whopping 735 competitors on Google for orange rabits and 530 competitors for purple rabits.

Put these misspelled terms in your meta description and you are golden. Put them in your content or title and you will most assuredly be in the top five. Am I missing something here? Did you mean orange rabbits and purple rabbits.

Neil