The plan is priced once and invoiced once. Hosting, the weekly updates, the nightly backups, the monitoring, the incidents and the quarterly report are all inside that number. There is no per-incident line, no bandwidth surprise, and no call that costs extra because it came on a Friday.
What sits outside it is the work of changing the site rather than keeping it: a new section, a redesign, a feature. Those are quoted separately, in writing, before anything starts, the same way the platform builds are.