OpenAI answers with budget GPT-6 Sol and Luna, halving token prices

OpenAI's GPT-6 Sol and Luna extend the GPT-6 family into cheaper tiers, trained with methods similar to the flagship Astra and offering higher usage limits plus coding and computer-use improvements. GPT-6 Sol is priced at $2/$10 per million input/output tokens — roughly half its GPT-5.6 predecessor — while Luna drops to an aggressive $0.10/$0.50. Both are available across ChatGPT Work, Codex, Plus, Pro, Business, Enterprise, and Edu, with Luna also reaching Free and Go users, and both are now on Amazon Bedrock and Microsoft Foundry.

The timing was the story: OpenAI shipped within hours of Anthropic's Opus 5.5, turning September 22 into a same-day pricing war. Sam Altman emphasized the models are 'half the price per token, and even less per task,' while Greg Brockman highlighted Astra-derived gains in professional work, factuality, coding, computer use, and alignment. Independent developer Simon Willison called Luna 'my favorite model for building product features thanks to its cost (and speed).'

Developers dissected the three-way economics on Dev.to — Opus 5.5 ($4/$20) vs Sol ($2/$10) vs Luna ($0.10/$0.50) — with r/LocalLLaMA's 'Cost of intelligence is dropping fast' thread (393 upvotes) capturing the mood. The consensus: great for builders, worrying for vendor margins, with Fortune quoting concern the race erodes profitability.

OpenAI also expanded ChatGPT Voice to use plugins (email, calendar, Slack) and run on Astra, Sol, and Luna. Separately — and reported as its own item, not annexed here — OpenAI expanded ChatGPT Ads to Southeast Asia and Taiwan. Watch whether Luna's rock-bottom pricing becomes the new floor competitors must match.