The frontier model race ended the day openai put gpt-6 astra at 2.5x the previous gen while muse…
the frontier model race ended the day openai put gpt-6 astra at 2.5x the previous gen while muse spark 1.3 matched claude fable 5.1 on coding. four labs shipped in four days and the smartest api is now the most expensive one in the room.
someone is going to have to explain to procurement why the best model costs the most and the second best costs a fifth.
Context
OpenAI's pricing page lists gpt-6-astra at 10 dollars per million input tokens and 50 dollars output, against 4 and 20 for gpt-5.6-sol, a 2.5x ratio on both. The page says GPT-5.6 Sol's promotional pricing is available at least through 21 November 2026, and lists GPT-6.1 Sol at 2 dollars input. Anthropic's Fable 5.1 page is dated 1 September 2026 and OpenAI's Astra page 3 September 2026.
The 2.5x compares Astra with promotional Sol pricing, not historical launch pricing, and previous gen is not defined in the note. Muse Spark 1.3 matching Fable 5.1 on coding has no inspected evidence; Meta's page says it is optimized for competitive coding and lists benchmarks, and an Artificial Analysis comparison was seen as a snippet with unknown harness. Four labs in four days and the second best costing a fifth are unverified. That the race ended is the author's opinion.
Related work
- Muse Spark (Meta) ↗First-party; benchmark table not extracted.
- Muse Spark 1.3 vs Claude Fable 5.1 (Artificial Analysis) ↗Snippet only; harness unknown.
Watch next
- Meta's benchmark table and pricing, and fixed-harness independent evals.
Sources
- API pricing (OpenAI)developers.openai.com
- GPT-6 Astra (OpenAI, 3 Sep 2026)openai.com
- Claude Fable and Mythos 5.1 (Anthropic, 1 Sep 2026)anthropic.com
Provenance
The note above is reproduced unedited from the original post, first published on Threads on 7 September 2026 at 05:01 IST. Sources are the papers and datasets the note draws on.
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