Full-Stack Developer for Custom MEP Cost Estimation Web App

We currently use a fully working Excel-based MEP cost estimation workbook for pricing MEP projects. All main formulas, calculations, and estimating logic already exist in the Excel workbook. I am **not looking for someone to develop the estimating methodology from scratch**. I need a developer to convert this workflow into a simple, flexible, database-driven web application. ### Core Requirement Each BOQ item must be flexible and can be priced using **any number of cost components**. For example, if I am pricing an insulated pipe item, I should be able to add: * Pipe * Fittings * Supports * Insulation * Cladding * Labor * Painting * Accessories * Any other required component For each component, I should be able to select data from a **Master Database**, such as: **Category → Specification → Size → Brand/Manufacturer → Supplier** The system should then automatically retrieve the **latest available price** from the database. Example: **Insulation → 25 mm → Armaflex → selected manufacturer → latest stored price** The same concept should work for pipes, fittings, valves, supports, equipment, cables, ductwork, accessories, labor, etc. I should also be able to: * Add unlimited cost components to any BOQ item * Use predefined costing templates when useful * Add or remove components manually * Override a database price manually when required * Fix/freeze a selected price for a specific project * Update master prices periodically in one central database * Use the updated prices automatically in future projects * Keep historical project prices unchanged unless I intentionally update them ### Other Requirements * Create and manage projects * Import or enter BOQ items * Maintain the existing Excel formulas and calculation logic * Master database for materials, weights, specifications, brands, suppliers, labor rates, standard factors and equipment prices * Different costing templates for pipes, ductwork, equipment, etc. * Indirect cost, overhead and profit calculations * Copy an existing project as a starting point for a new tender * Excel import/export * Simple and professional interface * Full source code ownership * No mandatory monthly software subscription * Standalone database-driven application This is **NOT an ERP, Odoo implementation, AI project, or company website**. The objective is to make our existing Excel estimating process faster and easier by avoiding repeated data entry and creating a reusable central cost database. The existing Excel workbook will be provided to shortlisted developers to demonstrate the formulas and current workflow. Please send 1–2 examples of similar costing, quotation, database-driven business applications, or Excel-to-web applications you have developed.