--- title: "OpenAI's new model runs tasks about nine times cheaper than Claude Opus 5.5, the model in Anthropic's S-1" description: "OpenAI published Terra's price sheet the same day Anthropic's S-1 went public: frontier capability at a tenth of the flagship cost, against a prospectus priced for a $1.5 trillion valuation." publisher: "The Inference" section: "Model" published: 2026-10-27T14:32:03.380Z modified: 2026-10-27T14:32:03.380Z canonical: https://theinference.org/article/openai-s-new-model-runs-tasks-about-nine-times-cheaper-than-claude-opus-5-5-the-model-in-anthropic-s-s-1 language: en keywords: "OpenAI, Anthropic, Model Pricing, IPO, AI Agents" --- # OpenAI's new model runs tasks about nine times cheaper than Claude Opus 5.5, the model in Anthropic's S-1 > OpenAI published Terra's price sheet the same day Anthropic's S-1 went public: frontier capability at a tenth of the flagship cost, against a prospectus priced for a $1.5 trillion valuation. The price of frontier intelligence fell again, and it fell on the one day this year when the market's only public price list for an AI lab was open for reading. On Monday, October 26, [Anthropic](https://theinference.org/markets/companies/anthropic) [filed its S-1 for a Nasdaq debut under the ticker ANT](https://www.cnbc.com/2026/10/26/anthropic-ipo-live-updates-ai-s-1-filing.html) [4]; the same day, [OpenAI](https://theinference.org/markets/companies/openai) shipped GPT-6.1 Terra, a model that reads screens and acts across applications, priced 50 percent below GPT-6.1 Sol [1]. Investors deciding whether to buy Anthropic at its mid-November debut, or to hold [Microsoft](https://theinference.org/markets/companies/microsoft) into its October 28 results, are now pricing a revenue line their rival reprices weekly. ## A tenth of the flagship price is the number that matters Not the headline cut. [OpenAI's own evaluations](https://interestingengineering.com/ai-robotics/openai-gpt-6-1-terra-50-percent-cheaper) say Terra matched its flagship GPT-6 Astra on Agents' Last Exam, a benchmark of professional tasks, at roughly one-tenth of Astra's price per token, and ran tasks roughly nine times cheaper than Claude Opus 5.5, the model Anthropic's prospectus sells [2]. Terra also scored 15 percentage points above GPT-5.6 Terra at about a third of the cost per task [1], and cut its factual error rate from 53.6 percent at low reasoning effort to 16.7 percent, falling to 4.3 percent at maximum effort, per OpenAI's reported evaluations [2]. *Chart: **Terra cut factual errors from over half of prompts to under 5** Bars comparing factual error rates on OpenAI's internal benchmark: GPT-5.6 Terra at low effort 53.6 percent, GPT-6.1 Terra at low effort 16.7 percent, GPT-6.1 Terra at maximum effort 4.3 percent.* *Factual error rate in percent on OpenAI's internal benchmark, by model and reasoning effort, per OpenAI's reported evaluations [2]. [2]* What changed for buyers is concrete: a model that can see a screen and operate software makes computer-use agents practical, but practicality depends on the cost per task, and Terra drops that cost by an order of magnitude. Capability stopped being the constraint; the price of running it now is. ## The prospectus is priced for a market Terra is repricing For Anthropic, the arithmetic is uncomfortable. Its filing reports [third-quarter revenue of $16.8 billion](https://theinference.org/article/anthropic-s-16-8-billion-quarter-is-the-number-holding-up-a-2-trillion-ipo), up 45 percent, against an $80.7 billion first-half loss and [valuation talk that has slipped toward $1.5 trillion](https://www.chicagotribune.com/2026/10/26/compaas-de-inteligencia-artificial-van-camino-a-lucrativos-debuts-burstiles/) from $2 trillion [3]. A price war already cost it [most of Replit's reported $100-plus million a year in coding spend](https://kalkine.com.au/news/general-news/what-does-openais-30-replit-discount-mean-for-aiq-nasdaqaiq), with discounts reported up to 90 percent in individual cases [3]. Terra extends that discounting from contracts to the published price sheet, and nothing in the filing shows how Anthropic's revenue survives a rival selling comparable capability at a tenth of the cost. ## Both sides hold real evidence Falling prices do expand usage; Anthropic's own prospectus reports that cheaper tasks drove adoption, with net revenue retention near 900 percent [5]. But a price sheet that halves in a quarter turns a valuation into a volume bet nobody has published numbers for. The decision rule before buying Anthropic or holding Microsoft: check the prospectus revisions through mid-November for pricing and margin language, and read Microsoft's October 28 cloud results for what enterprises actually pay per token. If margins hold while usage rises, Anthropic's line survives; if revenue per token keeps falling faster than usage grows, the valuation is the thing repriced, not the intelligence. ## Takeaway OpenAI's Terra matched its flagship at a tenth of the price and beat Claude Opus 5.5's cost by nine times, landing the same day Anthropic's $1.5 trillion S-1 went public; the prospectus must show usage growth outrunning the price cuts. ## Sources 1. [Business Today, OpenAI launches GPT-6.1 Terra with advanced computer-use capabilities at half the API price, 27 October 2026](https://www.businesstoday.in/technology/news/story/openai-launches-gpt-6-1-terra-with-advanced-computer-use-capabilities-at-half-the-api-price-563959-2026-10-27) 2. [Interesting Engineering, OpenAI's GPT-6.1 Terra delivers GPT-6 Astra-level results at 10% of the token price, 27 October 2026](https://interestingengineering.com/ai-robotics/openai-gpt-6-1-terra-50-percent-cheaper) 3. [Kalkine, What Does OpenAI's 30% Replit Discount Mean for AIQ (NASDAQ:AIQ)?, 26 October 2026](https://kalkine.com.au/news/general-news/what-does-openais-30-replit-discount-mean-for-aiq-nasdaqaiq) 4. [AP via Chicago Tribune, Compañías de inteligencia artificial van camino a lucrativos debuts bursátiles, 26 October 2026](https://www.chicagotribune.com/2026/10/26/compaas-de-inteligencia-artificial-van-camino-a-lucrativos-debuts-burstiles/) 5. [CNBC, Anthropic IPO live updates: AI lab's S-1 filing, 26 October 2026](https://www.cnbc.com/2026/10/26/anthropic-ipo-live-updates-ai-s-1-filing.html) --- OpenAI's new model runs tasks about nine times cheaper than Claude Opus 5.5, the model in Anthropic's S-1 — The Inference. Canonical: https://theinference.org/article/openai-s-new-model-runs-tasks-about-nine-times-cheaper-than-claude-opus-5-5-the-model-in-anthropic-s-s-1