Here are the four official pricing pages we used as references:
Anthropic Claude: https://claude.com/pricing
OpenAI: https://openai.com/api/pricing/
Google Gemini: https://ai.google.dev/gemini-api/docs/pricing
Anthropic Fable 5 / Mythos 5: https://platform.claude.com/docs/en/about-claude/models/introducing-claude-fable-5-and-claude-mythos-5
