Im looking for a simple free Wordpress e-commerce plugin in order to sell a few items like shirts, hats and stickers. The shirts come in multiple sizes so I need to be able to have an option to list the different sizes per item (ie variations). Each item will need to list the price of the item plus the shipping cost. I want people to simply click on a "add to cart" button to add items and then checkout by paypal without having to register. If you have personal experience with such a plugin, please let me know which one you use. Thanks.