I have evaluated a lot of open source ecommerce solutions lately. Most of them is too complex for my need, and Prestashop seemed to be the perfect balance of ease of use and design. But there are a few features I am not able to find and configure (if they exists). Hope someone can help. 1) I want to disable the possibility for users to register themselves as customers. 2) I do not want any prices to be shown unless a customer is logged in. 3) How to configure the discount rate (in percentage) for a customer. Is it possible to set the discount rate for each product or at least product groups?