Write an mobile application and website

Dear all ,, I would like to have e-commerce platform similar to [login to view URL] i want to have 2 mobile application one android and the other for Iphone i want to have a registration button and the user can register and he can chose if he seller or buyer , the seller can create his shop and upload/edit/delete his items via the mobile application with sample steps i would like to get the ability for the buyer they can import the photos from their social media account like facebook and instagram with the description i would like to get a search engine on the application the buyer can add comments on each items and seller can replay to him and the comments are public view each item must have viewers on it the buyer can chose his region/country to see if the seller can deliver the items to him or not if i get a good web design will be great , and i want it responsive design i can share with you my prototype to get closer to the idea , and i would like know the estimation price for this project