While osCommerce claims to be "the leading open systems e-commerce solution," there are low-cost PHP-based and similar alternatives that might be worth considering. Products like x-cart, LiteCommerce, and Quickstore are available for purchase, and pricing for the basic versions range between $100 and $200.

However, you'll also pay for any options you want to add to these systems. For instance, Quickstore's credit card plug-ins cost an additional $49.95, and other options such as "online catalog builder" cost from $50 to $100. Some users will decide that the advantage of buying a product gives them some assurance that the system and its modules will work properly. This may be especially true for people uneasy with user-supported software like osCommerce.

I was going to write up a nice sized article about osc and its competitors, the benefits of the cart, etc, etc. Every time I take on a project, I get asked the same question, ‘Which cart do you think is the better of them?’ every time, hands down, I say OSC.
Well, thanks to Scott Koegler and a strong agreeance of opinion, I have borrowed his article for you to read on OSC, the facts and the benefits

'Maybe you've realized that the e-commerce system you're using just doesn't do things the way you want them done. Or you want to add a particular feature to your site because you know it will improve sales. Or maybe you simply want to change the look of your site beyond your existing system's capabilities. If any of these apply to you, it might be time to look into osCommerce, the open source e-commerce system.

Selling online use to be about; spending thousands just to get the cart up then a few hundred for the Merchant account. That however is not the case anymore thanks to Paypal and carts like osCommerce.
With the helping hands of these guys, you can have a nice looking, functional site up with a few hundred of dollars.(or less if you have the time to learn it yourself) This also includes the full ability to accept payments from Credit Cards, manage customers, create invoices and more.

The most cost effective ecommerce solution on the market today is Oscommerce.com . How much does this functional and expandable cart cost? Nothing, zero, zilch. Thanks to our great Open Source Code. An all in one solution osCommerce can have you setting up products to sell, have a visitor sign up and pay via the OSC payment section, create an invoice for that client as well as deliver the product(if it can be transferred via email) or create a packing slip to be mailed out.

Managed ecommerce; Application Service Providers

A study of SiteSell.com (http://www.sitesell.com/ )

To start with…. This type of site is not completely without it’s merits, they exist, but if it’s of any use it’s for the very ‘nubile’ webPreneurs. Great as a starter. Once one has a grasp of business and the internet, control is everything. These programs take away much of that control in the guise of making your experience more user friendly, when in essences, you are merely giving up control for a lack of other options.