How does it serve the user to tell them the price is increasing but not from what / by how much?

I don’t remember how much I pay, but now I have to dig around to compare if I want to.

Don’t use dark patterns to retain customers. Use excellent experiences and delight.

A screenshot of a portion of an email from YouTube that says: To continue delivering great service and features, we're increasing your price to $13.99/month. We don't make these decisions lightly, but this update will allow us to continue to improve Premium and support the creators and artists you watch on YouTube.