I had it review a single, large commit with /code-review. It burned through over $50 in API calls, ran my account balance out, and output nothing.
The fable part appears to be that it's affordable by mere mortals. Anthropic support told me "too bad" when I requested a refund.
You pulled the arm of the slot machine and discovered why they call it the one-armed bandit.
Almost the exact same thing happened to me when I first tried opus, one prompt no output cost $60 in additional usage
Combine that with it forcing to pay by tokens on June 22nd