The short answer is, only if you never expect your site to change. But websites aren't printed brochures, and you shouldn't design or build them in the same way. Still, building a static web site traditionally has been viewed as the low-cost, and quick solution. When everyone had to chose between a static site and a custom-built site, there might have been some truth to it. But now, anyone can download from the Intertubes free, usually Open Source, content management solutions, and this has drastically altered the cost equation, to the point that static web sites are never the most cost effective solution. Don't believe me? I drew a graph to prove it:

Let's discuss Dynamic sites first, obviously they will initially cost more than either a static or pre-packaged CMS site because you'll have to define what you will build, hire programmers and designers to implement it, potentially you'll reinvent some wheels, or if you're smart try to integrate some already invented wheels. Dynamic sites can also suffer from "blank-slate" syndrome, since you're not necessarily constrained by an existing system, stakeholders can ask for exactly what they want and how they want it to work.

Next up static sites, why do they have such a steep cost curve? Maintaining and updating a static site is tedious, boring work. The kind of work that robots will be doing in the future. The cost of updating a static site depends primarily on the number of pages on your site. Changes which are trivial on another system, like updating your organizations phone number or the copyright year in your footer, may require you to edit hundreds of files. You can do things like use CSS to remove presentation from your actual HTML files or make use of Dreamweaver templates and library includes to hold reusable content like site headers and footers, but that's just automating the tedium. And God forbid something in that chain breaks and now you've got corrupted templates. Static sites also require either having in-house technical expertise to update and create pages, or hiring an external shop to do it for you.

So, what exactly did I mean by a "CMS" site? Most people have heard of Drupal, Joomla, and other CMSes. They provide a lot of functionality, or hooks to add new functionality, without having to hire programmers to build it all for you. Any CMS worth its salt has a way for your designer or webmaster to "theme" it with your design. Of course, it may not work exactly the way you want it to, or have the exact layout your designer wants, but even Free has a price.

How can a CMS be cheaper than a static site in the long run, and cost the same at the outset? Because no matter if you have a static site, customized dynamic site, or CMS based site, someone has to take the pretty Photoshop .psd file and make it into a usable set of CSS and HTML files. How long that takes is largely independent of what's driving your site. Some CMS's might be easier or harder to theme, but they're all in the same order of magnitude for effort. After the initial build out, the ongoing cost of maintaining a site is what will make up the overall total lifetime cost for operating your site.