Build a membership site! Based on wordpress

Hi, I need a membership site. I have some training ebooks which i want to sell. I will create a membership site where people will pay for subscription to the site. Once they have paid, all my hidden content will be visible to them. I only need two types of memberships, free and paid. These are the only two levels invloved. Let me know what more information you need. Will be looking for someone who can do this cheap.