Ask three shops what a website costs and you can get three answers that are nowhere near each other. That confuses people, and I do not blame them. Nothing in the quote tells you what is inside it. So here is what moves the number, from the kind of site you are buying to who builds it and what happens after launch.
Complexity and Functionality
Complexity is the biggest lever. A few static pages that say who you are and how to reach you is a small build. An online store with payment gateways, inventory management, and user accounts is not. Every one of those pieces has to be built, wired up, and tested. The more your website's design and functionality have to do, the more hours go into it, and hours are what you are paying for.
Design and Customization
Then there is design. A pre-made template you buy and fill in costs less than a site drawn around your brand, because most of the work is already done for you. Custom means somebody picks the colors, sets the type, and makes the whole thing hang together so it looks right and is easy to use. That is skill and studio time, and it shows up on the invoice.
Content Management System (CMS) Selection
The content management system (CMS) matters too. That is what you log into when you need to change your hours or post something new. WordPress is open source and used just about everywhere, which keeps it a cost-effective place to build. Proprietary or specialized platforms run higher, partly for the features they add and partly for the support they require. The CMS you pick moves the build price more than most people expect.
Integration and Third-Party Services
Most sites have to talk to something else: a payment gateway, a customer relationship management (CRM) system, a social media account. Each connection is its own small project, and some of them carry licensing fees on top of the build. Custom work against a complicated API costs more again, because somebody has to read the documentation, make it work, and then keep it working.
Web Development Expertise
Who builds it changes the number. Established agencies and experienced freelancers charge more because they have done this before and the portfolio shows it. Newer developers bid low to win the job, and sometimes that works out fine. But the cheap quote is only cheap if the site is still standing in two years and somebody picks up the phone when it is not.
Maintenance and Support
Launch day is not the end of the spending. Software needs updating, security patches land, things break. Some packages include maintenance after launch and some bill it separately, so ask which one you are getting before you sign. A small brochure site takes less looking after than a store processing orders every day, and the support price follows that.
So the spread in website prices is not random. It comes from what the site has to do, how much of it is built for you specifically, what it has to connect to, and who answers the email after launch. Work out what you actually need first, then read the quotes against that. A site built for your business costs more up front and stays useful a lot longer.