What does it cost?

Free for solo developers, and that is the product, not a trial of it. One person gets the whole method, every check, and the console for their own project.

The other plans exist for when more than one person is involved. On the Team plan the price is per seat, and every contributor gets the same checks with nothing to set up, plus a record of each phase that somebody else can read. That matters once the person reviewing the work is no longer the person who did it. The Sovereign plan is under contract, for organisations whose data has to stay inside a perimeter they define.

What each plan includes is kept in one place, the install page, so this answer cannot drift out of date with it. If it is just you, run the command above and start; there is nobody you need to speak to first. If you are a team or an organisation, the quickest route is to talk to us.