I want to build a platform/website

I seek to develop an innovative e-commerce marketplace connecting businesses with on-demand manufacturing and fulfillment solutions. The envisioned platform would facilitate multi-vendor storefronts while streamlining production workflows and optimizing shipping logistics. Vendors would be able to upload and sell custom-designed products without maintaining their own inventory, as third-party partners seamlessly handle printing, packaging, and distribution on the seller's behalf. Key functionality includes a responsive design allowing vendors to build and customize online stores, upload designs and product listings, set pricing and profit margins. The platform will integrate with various print-on-demand and dropshipping partners to dynamically pull real-time costs and fulfill orders through a single API. Administrative tools give site owners oversight of all system activity while configurable commission rates and payment processing offers flexibility. Project requirements also include user registration, secure logins, shopping carts and multi-channel sales reporting. By acting as a one-stop marketplace connecting independent entrepreneurs with an ecosystem of production resources, this platform aims to reduce barriers to online commerce. Strategic partnerships and streamlined processes help maximize profits for all involved. If developed successfully, it could empower small businesses and creators to manage virtual storefronts with global reach at minimal cost. Please provide your best estimate for designing and building out such a comprehensive e-commerce solution as outlined. I welcome your creative solutions and look forward to discussing details.