The report on findings is very interesting: 1451 acknowledged findings out of 23k candidates(~6%, not high but neither low).

But I didn't find the most important information (or maybe I missed it): how much did it cost to find 1451 security bugs?

We can at least put an upper limit on it. From https://www.anthropic.com/glasswing

    Claude Mythos Preview will be available to participants at $25/$125 per million input/output tokens
    ...
    Anthropic is committing up to $100M in usage credits for Mythos Preview