How much does MERN AI chatbot development cost in 2026?

POC chatbot on your actual data runs $12,000 to $20,000 over 3 to 4 weeks. Production MERN AI chatbot with RAG, guardrails, cost caps, evaluation suite, and streaming UI runs $20,000 to $50,000 over 6 to 10 weeks. Enterprise multi-channel chatbot (web plus Slack plus WhatsApp plus escalation to Zendesk or Salesforce) runs $50,000 to $150,000+ over 12 to 20 weeks. Dedicated MERN chatbot engineer starts at $3,500 per month. Ongoing LLM plus Atlas infrastructure typically costs $500 to $2,000 per month at moderate volume, an order of magnitude below Intercom Fin or Zendesk AI at the same conversation volume.