Building a comprehensive AI Legal Chamber Platform as described is a $250,000–$300,000 project over 12-14 months if built in India, or double that in the US/EU.
Recommended First Step:
Start with the MVP focused on RAG-based Case Law Search + Property Due Diligence. Property due diligence (reading sale deeds, generating reports) has immediate monetization potential and solves a very specific pain point for both lawyers and real estate firms, allowing you to generate revenue while building the more complex drafting modules.