Short answer: put the model behind a small Node.js contract, then test the same retrieved evidence against GPT-4o-mini, Claude Haiku, and Gemini Flash. For the stated production token comparison, GPT-4o-mini is the lowest-cost production-ready baseline at $0.15 per 1M input tokens and $0.60 per 1M output tokens. That makes it the first candidate, not an automatic winner.

For a fintech chatbot answering from a private knowledge base, portability is the constraint I would design around. A model that is cheap today can still be expensive to replace if the application leaks provider-specific message shapes, authentication, or retry behavior into every route. Keep those details at one boundary.…