It would also be great to emphasize that this only applies to the HIBP API, and the Pwned Passwords API will still be free. (It's mentioned about half-way through the article.)
I completely missed this because of skimming. Almost jumped the gun on subscribing. Use the pwned password API a lot. (I use the email-based one not at all.)
Hm, I didn't actually realize there was a separate Pwned Passwords API. Having trouble finding docs on it (could be becuase I'm a horrible googler).