BigCartel/Shopify Ecommerce clone

Hello, PLEASE READ CAREFULLY before you place your bid. YOU MUST HAVE CLEAR UNDERSTANDING OF BigCartel / SHOPIFY Shopping Carts. We are looking for bespoke eCommerce platform based on BigCartel/Shopify actual cart functionality. WE DON'T require signup pricing plans or user creation like those companies offer BUT a standalone shopping cart CMS that can be easily installed on any domain. BigCartel/Shopify is mentioned for example purposes only to give you the understanding on functions required and ease of use from administration side. full brief on product, category, shipping, photo etc fields can be supplied. Everything has to be coded with ease of use in mind. it has to have simple backend as BigCartel all shiny and simple. Once the eCommerce CMS is built its front-end has to be easy to skin/theme. Please let us know your price estimate, timescale, coding languages you will be using and previous portfolio of your work. IF you have a ready made solution that can be adjusted please provide links to demo.