Would the easiest way to determine how easy it would be to rank for a keyword be using the intitle:keyword function?
The search resolts 100,000- 100,000-500,000 500-000-1,000,000 1,000,000-5,000,000 5,000,000-10,000,000 10,000,00+ OMG
I am trying to focus more on long tail search terms. I find one that is searched atleast ten times a day and try to rank first for that term.
I use a similar strategy. I look for terms that are searched for at least 25 times a day (per WordTracker). Your cutoff is at least 10, which is probably more realistic for long-tail search phrases. I find WordTracker's free tool quite helpful.