Advice for new shopping cart in PHP or ASP.NET

I am in need of a "Shopping Cart".

My requirements are:

1. Allow customer to Add/Remove from, and Edit Quantities of Items in the Cart.
2. When the customer is ready to purchase, a "Purchase Order" 开发者_运维百科is sent to my client (instead of the items being sent to paypal for immediate purchase) - so my client can verify they have enough stock available before he then approves the order and sends the customer an Invoice.
3. It must be free or open source if you are going to refer me to an already-built shopping cart solution.

I am willing to build this using either ASP.NET or PHP.

Eagerly awaiting your advice! Lots of thanks in advance.

Jason

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As you know, there are numerous e-commerce solutions out on the net, and I bet one of them fits your requirements. My recommendation is to take a look at these two sites, to see if you find anything interesting there:

http://php.opensourcecms.com/scripts/show.php?catid=3&category=eCommerce http://www.microsoft.com/web/gallery/Categories.aspx?category=eCommerce