Which LLM gives the best results for AI agents and is cheap too?
After trying frontier models from OpenAI, Anthropic, Google and DeepSeek, a builder asks which LLM is both good and cheap for agents. The cost-saving pattern is routing by job: a fast cheap model for routine calls and a strong model only where reasoning matters. Most of the bill comes from long context, not the model tier, so short prompts and caching matter more than brand.