In an agentic pipeline, the output text is 2-5% of the total tokens used, so verbosity is a nonissue costwise. Although, higher verbosity could cause input to balloon faster and potentially cost more, but that would be captured by the cost-per-task metric.
But as noted by other replies, it's still lower than Opus/Sonnet.
You pay for chain of thought tokens as well. Ex: Imagine asking for a single number that takes 1h to compute
That's included in my estimate. Take for example Opus 5.5: https://openrouter.ai/anthropic/claude-opus-5.5
Currently for today, it's 1.19T input tokens, 5.41B reasoning tokens, and 4.29B completion.
Therefore, reasoning + completion is 0.8% of the total usage. Actually below my estimate!