The sky is the limit. You get complete unlimited access to all enterprise features for 30 days (we might even extend it if you ask nicely).
After your trial, pricing is between $10–30k per year, per production server, depending on feature tier.
Nope. Metabase Enterprise runs the exact same way you already run Metabase, meaning you get full control of your own production environment and upgrading is a Docker pull or .jar away.