Website + Interactive Sales Dashboard and Database Integration with Custom AI Chatbot

I'm exploring the development of a website and performance dashboard, similar in design, functionality and overall user experience to this example: https://naanco.com The project would include a responsive, branded website alongside an interactive, password-protected sales dashboard. Dashboard requirements: Daily, weekly and monthly sales and order reporting Interactive charts, filters, rankings and product-performance tables Revenue, order, average order value and product-mix analysis Live Google Sheets data integration with manual refresh An in-built AI chatbot able to understand and analyse menu and sales data from the dashboard General requirements: Mobile, tablet and desktop optimisation Custom animations and a polished, highly visual interface Hosting, deployment and ongoing technical support Reference UI examples for the dashboard are attached. What I need right now: Before moving into detailed requirements, I'd like a high-level understanding of feasibility and cost. Please provide: An indicative price range for a project of this scope. Give me a flat fee, not hourly rate. An expected timeline for design + development Any likely ongoing/recurring costs (hosting, maintenance, API usage, etc.) A rough estimate is completely fine at this stage — I'm not looking for a detailed proposal yet. I need a flat fee/rate from you for the project. Skills required: Web Development, Front-End Development, Dashboard Design, Data Visualization, Google Sheets API/PowerBi API, Chatbot Development / AI Integration, Responsive Design, UI/UX Design