I am offering to help a friend of mine who is setting up a business. They intend to sell almost entirely through a website and need a shopping cart system which allows categories and sub-categories (multi-level), product options (some may affect price), search facilities, customer registration and secure online payment. Some 'nice-to-have' extras would be; discount voucher options, multiple pictures per product, option to save shopping basket contents and some stats about purchases.
I believe I have enough technical knowledge to design and code the system myself, except from the secure requirements and the integration into a 3rd party payment system. However, I'm wondering if a quicker and cheaper option would be to find some free or lo-cost software that can be tweaked if necessary. If I am to be the technical support it would need to be a PHP/MySQL application.
Has anyone got any product recommendations, or should I just lock myself up in a room for a few months while I code ??
Thanks
Rich