Short answer
One page is enough when you have one main service, a clear price and customers from one town. You need more pages when you offer several services, work in several markets or want to appear for different searches. A simple website at modernizuj.me starts at EUR 300.
When does one page work better?
For photographers, consultants, small service businesses or campaigns. One page with a clear message, one call to action and contact details loads faster, is easier to maintain and often turns a visit into an enquiry more reliably. More on the simple website.
Structure of a one-page website
An introduction with a headline and button. The services. Examples of work. A price or range. Contact and map. All on one page, in the order customers ask. See the pricing.
When do you need more pages?
When you have several services, want a blog or need to appear for different searches. Every page is another chance for Google to find you. Start with one page and expand later with a business website.