Claude Opus 5's effort levels, and what they actually cost you

tldr: Claude Opus 5 costs (5 per million input tokens and )25 per million output tokens, exactly what Opus 4.8 cost. The “cheaper frontier model” coverage is comparing it to Fable 5 at (10/)50, which is a tier comparison, not a price cut. The effort control has five levels rather than the three widely reported, and changing it mid-conversation invalidates your prompt cache.