OpenAI slashes 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. GPT-5.6 Terra is cut 20% to $2/$12, and GPT-5.6 Sol gets a faster API mode at 2x price. OpenAI credits Sol with optimizing inference to cut serving costs by 20%.