Jewellery Billing Web App Creation

Project: Jewellery Billing Web App

I need a premium, modern and responsive web-based jewellery billing application for my business. It should work on both Android phones and Windows laptops/PCs.

I have attached a sample bill image. The generated bill should follow a similar professional format.

Main Features:

1. Bill Generation
- Customer name and mobile/WhatsApp number
- Automatic bill/invoice number and date
- Item/particulars
- Weight
- Less
- Net weight (automatic)
- Labour
- Rate
- Amount (automatic)
- Gold/Silver total
- Discount
- Bill amount
- Cash received
- Final balance
- Add multiple items

2. Automatic Calculation
All calculations should be automatic according to the formulas I provide. Rates and billing settings should be editable by me from the admin/settings panel.

3. Bill Output
- Professional bill design
- Generate PDF
- Print directly
- Save/download PDF
- WhatsApp sharing

Preferred WhatsApp flow:
Generate Bill → Generate PDF → WhatsApp → Select Customer → Send PDF

4. Bill History
- Save all bills
- Search by bill number, customer name/number and date
- View/reprint old bills
- Download old bills as PDF

5. Shop Settings
I should be able to change shop name, logo, address, phone number, bill heading, rates and other basic settings without contacting the developer.

6. Multi-Shop System
I may provide this software to other jewellery shops in the future. Please build it as a multi-shop/multi-tenant system.

Each shop must have:
- Separate login
- Separate customers
- Separate bills/data
- Separate shop name, logo and address

One shop must never be able to access another shop's data. I should be able to add new shops without rebuilding the application.

7. Premium UI
I want a clean, premium and modern jewellery-business UI, not a basic template. It should be fast and easy for daily billing and responsive on mobile and laptop.

8. Cloud Data & Ownership
The application should use a proper cloud database so the same data is available on my phone and laptop.

Domain, hosting, database, source code, project files and main admin account must be under my control. I need complete source code and access at final delivery.

9. Low Maintenance
Please tell me the expected yearly cost for domain, hosting, database and any other services. I want minimum ongoing maintenance and no hidden developer dependency.

10. Milestones
I prefer milestone-based development:
- UI + bill design
- Calculations + PDF/printing
- Database + bill history
- Multi-shop + admin panel
- WhatsApp + final deployment/testing

Final payment will be released only after I receive and test the complete working project on both phone and laptop.

Before starting, please send:
- 2–3 similar projects you personally developed
- Proposed technology/stack
- Total cost
- Timeline
- Hosting/database requirements
- Yearly running cost
- Confirmation that I will receive complete source code and ownership/access

Please discuss and finalize the calculation formulas with me before development starts.
Scalability & Storage: The application should be designed to support a growing number of shops and bills without requiring a complete rebuild. There should be no unnecessary hard-coded limit on the number of shops or bills. Bill data should be stored efficiently in a scalable cloud database. PDFs should preferably be generated on demand rather than permanently storing every PDF unless required. Please specify the expected database/storage capacity, current hosting limits, approximate number of shops/bills the proposed setup can support, and how upgrading will work if the application grows.