When is a keyword worth while???????

I know this is a question that is based on an individual's opinion, but if the key word competition is low (based on adwords) at what point does the monthly searches justify putting the time into making a micro niche site based around that keyword?

Attn MOD: if this is posted in the wrong location my apologies, and feel free to move it. thank you.

Quick snapshot for you

1. Exact match search is over 1,600 monthly searches.

2. No more than PR3 showing on first page of results.

3. SEO competition under 100k. This is the phrase searched in double quotes and shows how many sites mention the exact phrase which is total number of sites you will be competing against.

4. No other sites are well optimized for the phrase. Meaning, they don't have it in their title tag, meta description, URL, H tags and a few other factors. I would use market samurai for this and use the SEO Competition module to take a snapshot of top ten sites ranking.

If you go just on numbers and do not do the snapshots of top ten in Google you will shoot yourself in the foot. Reason being, there could be under 10k sites that mention the keyword phrase, but if they are all PR5+ authority sites you will not rank quickly.

I'm assuming you are doing niche marketing. If done right, you should be able to rank top 5 within 2 weeks.

5. .com, .net or .org EMD available.