The Anthropic writeup addresses this explicitly:

> This was the most critical vulnerability we discovered in OpenBSD with Mythos Preview after a thousand runs through our scaffold. Across a thousand runs through our scaffold, the total cost was under $20,000 and found several dozen more findings. While the specific run that found the bug above cost under $50, that number only makes sense with full hindsight. Like any search process, we can't know in advance which run will succeed.

Mythos scoured the entire continent for gold and found some. For these small models, the authors pointed at a particular acre of land and said "any gold there? eh? eh?" while waggling their eyebrows suggestively.

For a true apples-to-apples comparison, let's see it sweep the entire FreeBSD codebase. I hypothesize it will find the exploit, but it will also turn up so much irrelevant nonsense that it won't matter.

Spending $20000 (and whatever other resources this thing consumes) on a denial of service vulnerability in OpenBSD seems very off balance to me.

Given the tone with which the project communicates discussing other operating systems approaches to security, I understand that it can be seen as some kind of trophy for Mythos.
But really, searching the number of erratas on the releases page that include "could crash the kernel" makes me think that investing in the OpenBSD project by donating to the foundation would be better than using your closed source model for peacocking around people who might think it's harder than it is to find such a bug.

You don’t see the value of vulnerabilities as on the order of 20k USD?

When it’s a security researcher, HN says that’s a squalid amount. But when its a model, it’s exorbitant.