Those tools are great a finding some interesting keywords that you may have not thought of, or that didn’t turn up in your initial keyword research. However, as derekwong28 pointed out, that data is incomplete, and the estimates on prices and budgets tend to be way off. Take what you find with a grain of salt.
I operate an ad agency and have compared the data from those tools, and others, with the millions of keywords we manage and they, are never close and always miss the bulk of the keywords that I have loaded into campaigns. It best to think of them as keyword ideal generators, as well as competitive ad text gatherers.
It’s not like the early days when we could amass huge keyword lists where we throw in any keyword that had a remote chance of generating a click. Back then (2005), we could simply write very pointed ad text to filter out un-targeted traffic, while gaining a positive branding effect from all of the impressions that failed to generate a click. Today, only the highly targeted traffic from extremely relevant keywords will do, anything less will have a disastrous effect on the profitability of your campaigns.
The bottom line is that you can use tools like that to give you clues, or hints for what might work. Do not trust, or try to use all of the keywords from the tool in your campaigns, you must be very selective. Nothing will replace common sense and good judgment. Look at every keyword and evaluate for relevancy as well as commercial intent, those are crucial elements in your keyword selection process.
