Drupal e-Commerce is a package of modules to let you create your own online store. It is totally free, open source, rich featured and flexible.
With e-Commerce, you will be able to:
* Shopping cart and product 'look and feel' are themeable
* Create taxes, charges and discounts
* Subscriptions and recurring payments
* Receive donations
* Sell file downloads, shippable items, bundles or even customizable products
* Inventory management
* Payment and shipping plugins: The system can use PayPal, Authorize.net, eWAY, C.O.D. or you can roll your own.
* Invoice generation and email notifications
* Transaction and payment workflows
* Reports and sales summaries
* Customers can review their order history
* Run an auction site
* Charts and Statistics! (Soon...)
And more because e-Commerce is designed to be expansible