cautionary notice about new Fly pricing

docs/install/fly.md

@@ -8,7 +8,19 @@ In order to deploy Actual to Fly.io, you’ll need to use their command line int
 
 ### Creating a Fly.io Account
 
-First, you’ll need to sign up for an account. Go to [fly.io](https://fly.io) and click “Get Started,” then fill in the form. Note that Fly may require you to enter credit card details. See [their docs on how they use credit cards](https://fly.io/docs/about/credit-cards/) for more information. If you follow the steps in this guide, you will remain well within the free plan limits. For more details, check out [Fly’s pricing documentation](https://fly.io/docs/about/pricing/).
+:::note
+Fly's pricing structure has changed as of Jan 25, 2024.
+New accounts are now gifted $5 credit. That $5 credit is only spent when exceeding the [free allowances](https://fly.io/docs/about/pricing/#free-allowances) for apps.
+This is called the 'Hobby Trial' plan.
+
+If you create an *additional* organisation from an existing account on a 'Hobby Trial' plan, that organisation will directly start on the 'Hobby' plan, which costs $5 per month as a base rate + usage outside of the free allowance limits.
+This has been confirmed by [Fly staff via their forum](https://community.fly.io/t/i-got-charged-today-for-the-hobby-plan-and-im-confused-as-to-why-cause-fly-io-didnt-send-any-emails/17969/8?u=tjex).
+
+You can therefore still sign up and host your Actual Budget instance with Fly for free, as the usage will not exceed the free allowances.
+:::
+
+To begin, you’ll need to sign up for an account. Go to [fly.io](https://fly.io) and click “Get Started,” then fill in
+the form. Note that Fly requires that credit card details for sign up. See [their docs on how they use credit cards](https://fly.io/docs/about/credit-cards/) for more information.
 
 ### Accessing the `fly` command line tool