Basic Shopping Cart Script PHP

I have a website that allows the sale of photos. You can chose from 4 different sizes for each photo and there can be an unlimited number of photos... anything from about 100 to 600. Have a look at: [login to view URL];WPCodeE=b632dere click on the image and get in to the system, and see the shopping system at the bottom of the page. needs to have a basket and that basket needs to get some payment info from a MySQL DB. Very Small Budget, but must be quick...