TL;DR
Marketing sites: R35k–R120k. Custom web apps: R120k–R450k+. The number is set by integrations, not pages.
What you are actually paying for
You are paying for decisions, not pixels. Anyone can install a Next.js template. The cost is in choosing what to build, what to ignore, and what to wire to which API.
What is worth paying more for
Performance budgets, real analytics from day one, accessible defaults, and an actual launch plan.
What is not worth paying more for
A custom CMS for a site that needs eight pages updated twice a year. Use Sanity. Move on.