Using a shopping cart might seem expensive, but wait until you hire a developer to build on something like Joomla or Wordpress. You will be rebuilding the wheel. These are basic CMS systems and while they can have shopping elements included, they aren't really built around the functionality of a shopping cart and you will spend quite a bit making them so. You would also have to be very careful about how you hosted credit card information, as most developers building around a CMS will not do this properly.

If you are looking to add social elements to your site, you might want to keep a Volusion site and then have a link on your site that goes to a forum.