OpenAI cuts GPT-5.6 Luna price by 80%, Terra by 20%, adds fast mode for Sol

OpenAI reduced GPT-5.6 Luna pricing by 80% and Terra by 20%, and introduced a Fast mode for GPT-5.6 Sol delivering up to 2.5x speed at 2x the standard price. The lower prices also apply to usage in Codex and ChatGPT Work.