eCommerce Solutions
The two best solutions I know of currently:
Please check my updated post here: https://www.wakingmedia.com/2013/01/add-custom-fields-to-google-checkout/ – I’ve posted a lot of additional shopping cart info.
BigCommerce – proprietary, php-based, starts at $14.95 a month for 100 products – https://www.bigcommerce.com/plans.php
Magento – open-source, starts at $15 a month for 100 items – https://go.magento.com/plans/