Lite allows you to have a 7 day trial for $7. After the trial ends, it costs $99 per month or $990 per year. This plan allows you to track up to 5 projects (websites) and track 500 keywords per project. You can search 25 batches of keywords per day, but you can search up to 10,000 keywords per batch. I like to use it to search multiple ideas for long tail keywords at once so I don't use up all my searches.
Keyword explorer, which was released few weeks back is one of the most exhaustive tools that we have see off late. Keyword Ideas, Phrase Match and KD help content marketers to align their content marketing efforts with organic search trends. Apart from that from an on page point of view, the tool gives everything that modern age webmaster need to track their overall performance.