For most of our sites, we use Joomla! as you know. Occasionally we have a need for a site that's just a shopping cart. We review a client's needs and try to determine which is the most cost-effective and functional for them. One recent project led us to an ecommerce platform called BigCommerce. We were very impressed with the system and decided to become a reseller. If you know of anyone who needs just a shopping cart, let us know. This may be a good option for them.