Ask HN: What is the best way to hire/find someone to write a biography?

Tough one. I don't have direct experience of writing a biography for someone else, but as a writer, I would guess it would be quite expensive. It depends though. If the background history is already compiled, and there's perhaps a rough draft showing sequence of events, the price could be a lot lower. I would imagine it would be a few thousand.

If you have some spare time you could also hire a writing coach and get them to help you write it.

Having had local newspapers write about close family members of mine, I’d encourage you to reach out to freelance journalists and see if they’d be interested. They may do it for less compensation in exchange for the exclusivity of the story, and they typically bring other skills to the table that are useful when telling a person’s story (interviewing people, basic investigation, etc).

This is my general advice without knowing the details of what you’re after.