WooThemes.com is a web based market place for the WordPress themes, template and plugins. The products of WooThemes.com are particularly designed for the ecommerce websites. WooThemes offers 30+ responsive WordPress themes. Most of the products available at WooThemes.com are for free of cost but it also deals in the commercial product as well.
All themes come with access to support forums, tutorials, and videos.
Most themes cost $79 (one-time fee) or you can become a member for $399 (first year) + $150 each year