You DON'T look at the number of pages indexed for a keyword to judge competition. It is not a good incator of how hard its going to be to rank number 1.
What you need is to get SEO for firefox, which is free. Then type in your keyword in Google. SEO for firefox will augment the listings to show a bunch of stats about each website which currently ranks, it wil show PAgerank, yahoo links and loads of other stuff.
I normally pay attention to the number of links according to Yahoo.
At first I wouldn't touch a keyword where the top 3 had more than 4,000 links on average. Now I stick to keywords around that average. These keywords are not hard to rank for with about 800 targeted links from linxboss.
You always want to be analyzing the number of links the top 3/10 have, the 'number of pages' Google shows is absolutely useless, don't listen to people who tell you otherwise.