Develop Product Marketplace mobile app (& website) with chat and POS .(Like offerup , letgo , carousell , mercari ) -- 2

Edit Update: Looking positively towards the following route : using Modesy as building block (A CodeIgniter based website [login to view URL] ) and creating mobile apps with ionic. (Developer opinion welcomed ) Looking for fast development. Budget is flexible. Features required (Would prefer the tech stack be flexible enough to develop the desired features in future): All users to have capability to be a buyer or seller from same app Buyer seller to have post(ad/listing) based chat. Chat to include attachments, size set by admin. The inbox history remains until set time/forever. All buyer seller Chats(including attachments) be accessed(read) from admin panel. (Desired : Chats can be deleted from admin panel) ---This feature is required for security against frauds. Login with Mobile OTP only. Browsing is allowed without login. Seller issued Coupons infra or the desired feature. (Desired: Chat to contain infra for "Make offer , Accept/Reject/Counter offer". Buyer to get checkout at negotiated price.) Shipping rate table based calculator Infra to charge seller to post ads(packages) Infra to charge seller to highlight ad( feature ad packages). Featured ads will have a featured mark and will will overwrite the default sorting and be above(eg: Every 6 ads should contain at least 1 featured ad. This settings can be tweaked by admin) Webview payment gateway Sitewide available coupons infra (both fixed and percentage). (Desired : coupons be specific to products sale, post ad package and highlight ad package) Ads can be added by seller from same app. App should be able to use phone's camera while adding product. Commission will be charged to seller for every sale. Commission rate can be set from admin panel, to be used to generate invoice to seller. Checkout page will add a "inspection service charge" to the total. This will be calculated based on a <fixed minimum + percentage of order value>(eg ₹250+0.5%) rounded of to nearest 100, these can be changed from admin panel. Buyer can untick this addon. Products have under category and subcategory(category meta can be updated from admin panel) A blogs section , only admin writes. Will contain videos. Seller and Buyer address will be mandatory during listing and checkout. As the same will be used to calculate shipping charges. (Desired: An address fields are prefilled using customers GPS, although 1st line of address will be blank and mandatory) Report abuse for listings and report user, admin panels gets notification Share post Order History and item marked sold. If integration with payment gateway success not possible. This would be done manually by admin. Every listing to mandatorily have weight , Length breadth and height fields filled. As they will be used to calculate shipping. All listings will have to be approved by admin Basic search ,sorting types by on time and price Listings to have support for at least 5 pictures App is Only English Adequate security Desired: Advanced security Seller payout infra when order is marked completed by admin. Banners infra Recently Viewed Products Popular Products tags added to listings, tapping them shows all listings tagged with tag Recent search dynamic filters based on the category Wishlist Listing to have short video of product allow zoom on images Comments on listings. (Also they can be moderated from admin panel) Admin and Super admin (privilege distribute) API integration with DTDC India and order tracking infra Users can save multiple addresses in their profile Seller profile to have image Infra for referral code Additional Services Required: Android and iOS Publishing Hosting and server setup installation Support for 60 days or more post publishing 3 or more revisions allowed