You wanna know the secret to significantly raising API rates without complaints?
You raise rates to a ridiculous number, drag out negotiations with devs and let them drop the news to their users, wait a bit for the revolts and news stories to happen, then make a press release saying "our bad, we love you guys so much, we 'found' a way to get our API prices down".
After all of that, API prices are still higher than reasonable, but all the users and devs are all happy and news stories go out saying how the users and devs won and got a better deal. All while you got the price increases that you wanted.
Honestly, I'd take this, because I think the far more likely scenario is that they just ignore all of this brouhaha and aren't seriously impacted as a result.
You raise rates to a ridiculous number, drag out negotiations with devs and let them drop the news to their users, wait a bit for the revolts and news stories to happen, then make a press release saying "our bad, we love you guys so much, we 'found' a way to get our API prices down".
After all of that, API prices are still higher than reasonable, but all the users and devs are all happy and news stories go out saying how the users and devs won and got a better deal. All while you got the price increases that you wanted.