Checking competition with exact search gives you an idea of the competition that targets your exact key phrase, but regular people don't search using quotes, so you also need to evaluate the broad search competition.

If you use firefox, get the seo quake plugin. Then search in google for broad match and have seo quake return for you the number of links each of the result pages have, that will give you a much better idea of what you'll need to do get on page one.