When you are building your website one of the main decisions you will need to make is do I use a CMS or not and if so which one?
If you are having a website the requirement for a CMS can vary and will Ineviatibly end up being slightly more expensive. The idea of having a CMS is that you or one of your colleagues can update your website yourself. However in reality you have to ask is this actually going to happen or even having had a CMS put in place are you still going to be reliant on the website developers for updates?
All CMS systems have a learning curve and even if you are using a CMS that you have used previously you will, in all probability, require some training as most CMS builds differ depending on who has built them. Suprisingly even after having a CMS system put in place a lot of clients still use their development team to update the website.
If you have considered all of this and still think that a CMS system is benefical, the calculation should be predicted usage against potential maintenance costs, then the next question should be which CMS should I use?
When choosing a CMS system you should have a good look at what is available and scope out what you require from your website now and in the future. The CMS system you choose will determine how your website can be developed over time and the cost of maintaining it and the potential of changing suppliers if you ever need to.
Open source (which means the code is freely available) CMS systems tend to be cheaper to produce and can be maintained by a wider range of developers. The main drawback tends to be security of your site as due to the code being openly available to anyone hackers tend to review code and try to find security flaws, however regular updates will resolve this simply.
On the flip side if you go with a vendor your site may be more secure however you will find the site more expensive to have developed and will be tied into their development team as well meaning issues may take longer to fix and your website can become out of date technically.
So whatever CMS system you choose whether it is Wordpress, Drupal, Joomla, Magento, Sitecore, Umbraco, Adobe Business Catalyst etc etc etc... Make sure you think long and hard about your choice, not least do I actually need a CMS.