1) What is the difference between a fancy product designer for $ 29 and a plus for $ 9?
2) Is the entire "checkout" included in the plugins? Like here: http://fancyproductdesigner.com/product/bottle/
1. Plus is an addon, which requires the basic plugin for $29.
2. No sorry, the jquery plugin does not include any checkout process, you have to code that by yourself. If you want to have a fully integrated shopping system, you need to purchase the wordpress/woocommerce version.