The flagship price war just turned into a deflation spiral. anthropic’s opus 5.5 launched at $4/$20…
the flagship price war just turned into a deflation spiral. anthropic’s opus 5.5 launched at $4/$20 per million tokens, the first opus priced below its predecessor, and openai’s gpt-6 sol answered at $2/$10, exactly half the rate.
the frontier is now a commodity with a ticker.
Context
Verified date: Anthropic introduced Claude Opus 5.5 on Sep 22, 2026 at $4 and $20 per million input and output tokens, which it says is 20% less than Opus 5. Simon Willison's Sep 22 price table lists GPT-6 Sol at $2 per million input and $10 output, and Claude Opus 5.5 at $4 and $20.
OpenAI also introduced GPT-6.1 Sol, which it says nearly matches GPT-6 Astra on agentic coding at one-fifth of Astra's standard prices.
The $4/$20 for Opus 5.5, its 20% drop from Opus 5 and the $2/$10 for GPT-6 Sol match the sources, and $2/$10 is exactly half of $4/$20. That Sol 'answered' Opus is a sequence claim; the sources read show both prices on Sep 22 but not who moved first. 'The first Opus priced below its predecessor' was not seen in the sources read, so unsupported here, not refuted. 'Deflation spiral' and 'commodity with a ticker' are the author's opinion.
Related work
- Anthropic pricing docs ↗Current price table.
- Simon Willison's price table ↗Sep 22, 2026.
- Anthropic Opus 5.5 post ↗Sep 22, 2026.
Watch next
- Check Anthropic's pricing history to see whether any earlier Opus launched below its predecessor.
Sources
- Introducing Claude Opus 5.5, Anthropicanthropic.com
- Claude Opus 5.5, GPT-6 Sol, GPT-6 Luna, and a new price, Simon Willisonsimonwillison.net
- Introducing GPT-6.1 Sol, OpenAIopenai.com
Provenance
The note above is reproduced unedited from the original post, first published on Threads on 1 October 2026 at 02:47 IST. Sources are the papers and datasets the note draws on.
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