Bare Minimums

It's technically possible to host a website on a number of free services. These have a number of restrictions, typically including mandatory adverts, tracking cookies for your users, being hosted on a predetermined domain instead of your own, and being either limited to a static site or to a particular technology stack.

Optimal Minimum

A domain name with shared hosting is the next step up.

Domain names are available in a variety of top level domains, which has a large impact on yearly costs. A .com domain which has not yet been registered will typically cost between $10-$15 dollars a year (In 2021).

Commercial

A dedicated server or VPS is a step up over shared hosting, both in terms of performance and security.

Such a service might cost $100 or more depending on your needs.

Other costs may include commercial SSL certificates, software support, and other fees.

Enterprise

For huge websites, the kinds of websites which are household names, costs can become quite large. Fortunately the vast number of websites will never reach the expenses incurred by such sites.