You need a content Management system if you have regulary changing Data (like Prices ...) on your webpage. For this we offer you typo3 the leading open source cms from europe.

Typo3 offers you a very powerfull administration backend to your Webpage.

There is a lot of literature and online documentation in different languages available.http://typo3.org/documentation

For 50$ a year we can give you full access to the Content Management System.