The sky is the limit. Yout get complete unlimited access to all enteprise 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. Learn more about our price tiers here.
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.