Do You Really Need a Keyword Explorer Tool?

If you are serious about getting traffic via Google or even YouTube, then you kind of have to have this tool. It's not the most expensive tool, although it can be, depending on how much you use it. I pay for the annual subscription so it's a little bit cheaper. But when we're talking about like an online business and doing SEO, do I want to spend $1,200 a year on this software?