SE Results - Competitive #?

What # of search engine returned pages constitues what we could term as a

COMPETITIVE

number for a keyword or keyword phrase?

I don't think that you can give it a number. There are lots of SERPs that have very few competing but they are for products or product groups where a lot of money changes hands. My root keyword has less than 200,000 competing but I finally made it to #7 with PR7 and tons of anchor text links. Sites above me are PR9/PR8.

My main efforts go to second level keywords and I hold #1 or #2 for lots of them.

Another search term that I optimize for has over 3,000,000 competing and I am #3 with a PR5. This one brings me massive amounts of traffic with a small amount of sales - but the sales still justify the bandwidth.

The number competing does not determine the competetiveness of the SERP - instead its the amount of money flowing through.

The main keyword search term in my field is returning about 117,000 pages on Google. It thins out after that.

Hope I'm headed in the right direction.

Although I agree with Egol, I do have my own gauge that I use when determining if I even want to try to compete for a keyword. Generally, if the results returned is 500,000 or less, I feel like I can reach the top 5. More than that would probably involve more time that I have to spend.

My gauge is to look at the PR of the top five sites... I figure that I can build better optimization, content than most people, plus I can put up a ton of anchor text - so, if I think that I can compete in terms of PR, I'll go for it.

Also, I frequently only commit enough resources to earn #2 or #3 or even #4 for a specific product search term. I'll put a dynamite price in the title tag and that will pull in the sales. Beating the PR9 or PR8's above me in the SERPs is cost prohibitive, so I simply undercut them in the title tag.

My competitors have powerful PR but they are real slugs when it comes to updating their site and building good informative content. That's one place where I kick their butts. :-P

One caution.... you can get into a price war with this approach. I've started a few.

Checking the number of "sponsored" results for the KW on Overture can also be a useful indication.

Try 59,000,000 results, with #9 ranking, that has taken some time.

EGOL, makes a good point on updating the content. I have found for a long time that the more I update a particular page with good information the more likely I will stand a chance a betting the competition.
Additionally, you know it competitive when those webmasters out there pull out every keyword rich domain and page name they can come up with. for example the first 20 results are domains like: keyword-keyword-keyword-keyword.com/keyword-keyword-keyword-keyword.html

So very annoying and horrible looking in the results.