OpenAI cuts GPT-5.6 Luna price by 80%

GPT-5.6 Luna now costs $0.20 per million input tokens and $1.20 per million output, an 80% drop; Terra is 20% cheaper at $2/$12. Sol gains a 2.5x faster API mode at 2x price. OpenAI credits Sol with optimizing inference, cutting serving costs by 20%.