More than a long piece of string? Of course it depends.
Basically the more you expect from your website project, the wider the range of features and functions, the more bespoke the design, the more complexity you build in, the more content you have, the more it will cost you.
But these days you can do so much for FREE.
E.g. We were paid to to develop a hyperlocal web publishing service, which offers the basics completely free. We built OurLocality using WordPress in multisite mode. There are hundreds of templates and plugins adequate for most starter projects. It has the ability to map your own domain, which has to be purchased separately and requires a small setup fee.
Of course OurLocality is a DIY platform, so you need a bit of time and lots of practice to make your site perfect.
And there are many other DIY setups and open-source systems that are seriously powerful too.
But not all of us have the know-how or indeed the time, which is where the principal costs tend to come in if you want to delegate the job to someone else.