Complete E-Commerce Website Setup

I am launching an online store that will sell my own “Website Full Design & Setup” service and I need the entire e-commerce environment built from scratch. The look has to feel modern, uncluttered and professional, with a neutral-tone palette that remains consistent across desktop and mobile views... (Budget: $30 - $250 USD, Jobs: Content Management System (CMS), eCommerce, HTML, Payment Gateway Integration, PHP, SEO, Web Development, Website Design)