So you want to use the very best keyword tracking tool possible, right? Makes sense.
You should make it your goal to use the best information, and the best tools, in every aspect of your internet campaigns.
But how do you know what's "best"? What does 'best' mean for you? How Do You Define Best? What is your marketing plan? Are you an article/bum marketer, or do you focus more on PPC? Do you have a little money to invest in software, or is money tight? How sophisticated are you at programming? Is ease of use important, or do you like to code a bit yourself? These are some of the questions only you can answer (and you need to).
I've always lived by the adage, "You get what you pay for".
This usually serves me well.
I remember starting out and trying to find the cheapest hosting possible.
I later needed to upgrade since the 'cheaper' one did not support enhanced php.
Point is, in order to have a flourishing internet marketing business, you need to treat it like a business.
Ask yourself "Is your Business Worth Investing In?" Of course, you want to be wise about your investments.
Just because a tool costs more, it doesn't mean it's best for you and your business.
One thing you want to avoid is paying a monthly fee for a tool.
Invest in some good software once, and enjoy great keyword tracking for the rest of your internet marketing career.