Mistral Small 4 is the cheapest at $0.15/$0.60 per million tokens — 97% cheaper on input and 98% cheaper on output. For a model with similar capabilities, DeepSeek V4 Pro at $0.435/$0.87 offers the best balance of quality and cost savings (85% cheaper).

DeepSeek V4 Pro costs $0.435 input / $0.87 output per million tokens, compared to Sonnet 4.6's $3.00/$15. That's 85% cheaper on input and 94% cheaper on output. For a typical workload of 1M input + 500K output tokens per month, you'd save approximately $83,112 per year.

GPT-5 at $1.25/$10 per million tokens is 58% cheaper on input and 33% cheaper on output than Sonnet 4.6. It offers 272K context and strong performance across most tasks. For teams already in the OpenAI ecosystem, it's a natural fit at a lower price point.

Mostly yes. Many alternative providers offer OpenAI-compatible APIs, so switching often requires just changing the API endpoint and key. DeepSeek, Together (Llama), and several others support the OpenAI API format directly. For providers with different APIs, tools like APIpulse generate migration code automatically.

For coding tasks, Claude Opus 4.8 ($5/$25) remains the strongest but is more expensive. DeepSeek V4 Pro ($0.435/$0.87) offers surprisingly strong coding performance at 85% less cost. GPT-5 ($1.25/$10) is also excellent for code generation and 58% cheaper on input tokens.