Custom Multi-Store POS/PWA Development

I am looking for the development of a custom multi-store POS/PWA for 3 independent WooCommerce stores that share the same physical checkout.

The main goal is to have one Spanish-language POS where staff can sell products from all 3 stores in a single transaction and generate one receipt for the customer.

The system should work offline-first, allowing sales to continue without an Internet connection and synchronizing with the 3 WooCommerce stores once the connection is restored.

WooCommerce would mainly be used for products, SKUs, inventory, and orders, while the POS would independently manage sales, customers, credit, payments, discounts, promotions, cash registers, held sales, reports, and activity logs.

The POS should support barcode scanning, multiple cash registers and devices, split payments, thermal receipt printing, shared inventory between stores, and synchronization between the 3 WooCommerce installations.

The application and all user-facing elements must be available in Spanish.

I am looking for an MVP quotation including development cost, estimated timeline, technology/architecture, hosting and maintenance costs, and any third-party licenses or additional costs.

I’m attaching a document with all the details and requirements for the project. We understand that this is a fairly large project, and we’re not in a rush, so there’s no strict deadline.

At this stage, we’re mainly looking to get an accurate idea of the development cost and estimated timeline, as well as what would be included in your proposal.