It's free for personal use, I believe, but they charge for business use. (And this is *very* much business use.) According to this page, it's $30-100/user/year, depending on how many users you have. Those prices are neither unusual nor unreasonable, but I have to be penny-pinching for the time being.

(Actually, it's really very ambiguous about personal use. It's kinda-sorta free for educational use, but I don't see *anything* talking about personal use licenses. I suspect that, if it's just one or two people, they just don't care much...)