› Claude Opus 5.5 and GPT-6 Astra scored highest in my test across 10 languages, with 98.7% and 97.8% of the points.
› They are also the most expensive.
› I compared the official ways to access both models and used my logs from October 24, 2026, to work out which costs least for light, medium and heavy use.At a glance (as of October 24, 2026)For up to about 35 tasks a day, the API costs least: a typical short task costs about $0.019 on Opus and $0.017 on Astra.If you can wait: Anthropic Batch and OpenAI Flex or Batch cut the price in half.GPT-6 Astra in chat is available only with ChatGPT Pro, starting at $100.
› The $20 Plus plan includes Astra only in Codex and ChatGPT Work.Opus in chat is included in Claude Pro for $20, while Max 5x for $100 returns its price in API credits.Every way to access Opus 5.5OptionPriceTypical short taskCatchStandard API$4 / $20 per 1 million tokens$0.019You also pay for the conversation historyAPI Batch50% lessAbout $0.0095Delayed results; for automated workflows onlyClaude Pro$20 ($17 per month billed annually)Included within limitsFive-hour limit and an uncapped weekly limitClaude Max 5x$100Included within limits, plus $100 in API creditsCredits do not roll over to the next monthThere is also prompt caching: cached input costs $0.20 per million tokens instead of $4.