Dynamic content sites allow you to add/edit content on pages, news stories, press releases, calendars, etc. Content is maintained in a database that you update from a password protected page.
The cost of development of dynamic websites vary depending on the type of content and the way you want to update it.
The Atlanta City Development Corporation in Atlanta, Texas needed a community site where they could announce civic events, important community news, and publish a community calendar. They wanted photos of the city and a contact form that could send email comments to a variety of civic officials. They also needed simple back-end tools to maintain the content. Visit AtlantaTexas.org.