This is often called "website flipping" or digital real estate. You are buying the traffic, content, and revenue stream of an already active site.
Use dedicated marketplaces that list vetted websites for sale. how can i buy a website
Agree on a price based on a multiple of its monthly profit (usually 24x to 45x). This is often called "website flipping" or digital
Flippa is the largest marketplace for smaller sites and domain names. how can i buy a website