Create a responsive WordPress site with booking and payment functionality

I am looking to build a professional yet simple website focused on selling digital products, mainly online courses. The website should have a clean, modern design and be easy to use for both users and administrators. It must support essential and modern website features, including: * Digital product and course listing * Secure payment integration * User accounts and dashboards * Course access after purchase * Ratings and reviews system * Admin panel to manage courses, users, and content * Responsive design (mobile, tablet, desktop) * Fast loading speed and good security practices The platform should be scalable, allowing new features to be added in the future, while keeping the initial version simple and efficient. Please include in your proposal: * Estimated cost * Timeline * Technology stack you recommend * Examples of similar projects you have completed I am open to suggestions that improve performance, security, and user experience.