Customizing a PHP shopping cart script

I have the dreamweaver shopping cart extension cartweaver I need to customize (customization is allowed by the way) this script so that I can add pricing to the options and add the ability to have the overall price of the product marked up by a percentage when a particular option is selected: IE a table in oak is $200, the customer decides to add a 3 leaves to the table at $50 each. They finally choose to change the wood the table is made out of to cherry which is a 35% upcharge on the table base price and the price of the leaves. I need to be able to add options that have different percentage mark ups (wood types). This may entail MySQL database improvement/modifications as well. This script installs cart components into a webpage I dont need these components modified just the admin/back end & actual cart mechanisms that handle product upload/input and check out that are located on the server. ## Deliverables 1) Complete and fully-functional working program in executable form as well as complete and extremely well commented source code of all work done on the original and customized scripts. 2) Deliverables must be in ready-to-run condition. A software installation package that will install the software in ready-to-run condition on the platform(s) specified in this bid request. 3)Fully functioning database creation script that is fully compatible with the modified cartweaver scripts 4)fully prepared & laid out file structure including all necessary file, scripts, includes etc in the folders they are supposed to be located in for proper functioning of this script/shopping cart 5)Full integration with the dreamweaver extension suite inserted page code snippets. 6)Bug and error free 7)All deliverables will be considered "work made for hire" under U.S. Copyright law. Buyer will receive exclusive and complete copyrights to all work purchased. (No GPL, GNU, 3rd party components, etc. unless all copyright ramifications are explained AND AGREED TO by the buyer on the site per the coder's Seller Legal Agreement). ## Platform Dreamweaver CS3, Windows XP/Vista PHP 4+ MySQL 4+ Apache 1.3+ linux server operating system