Add pricing details for region pinning (multiple pages) (#2059)

Added limits and pricing information for region pinning feature.

It's related to our rollout of this blog post tomorrow:
ngrok-private/frontend#2227

Also changing the actual pricing page:
ngrok-private/frontend#2248

---------

Co-authored-by: Amp <amp@ampcode.com>
Co-authored-by: Niji <niji@ngrok.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: 4 people

snippets/guides/region-pinning-content.mdx

@@ -196,4 +196,22 @@ The `resolves_to` parameter uses the following PoP names:
 | **South America** | São Paulo | `sa` |
 | **Regional Aliases** | Global | `global` |
 | | Europe _[coming soon]_ | `european-union` |
-| | United States _[coming soon]_ | `united-states` |
+| | United States _[coming soon]_ | `united-states` |
+
+
+
+## Limits and pricing
+
+<Warning>
+This feature is temporarily free to use on the Pay-as-you-Go plan. 
+
+Billing & metering will be enabled soon, so if you use this feature, you may start seeing charges at any time. You can monitor your usage [in the ngrok dashboard](https://dashboard.ngrok.com/billing). 
+
+We'll update these docs when this changes. 
+</Warning>
+
+This feature is only available on the Pay-as-you-Go plan. [Learn more about ngrok plans](https://ngrok.com/pricing).
+
+You can have up to 100 region-pinned domains. This is the same as our total domain limit, so most customers should be fine. Feel free to reach out via support if you need more. [Learn more about limits](https://ngrok.com/docs/pricing-limits)
+
+Region pinning will cost **$0.02 per active endpoint hour** (in addition to the standard endpoint rate), per endpoint on a "pinned" domain. An endpoint is considered active if it receives any traffic in a given hour. If your endpoints with pinning enabled don't receive any traffic, you won't incur charges for this feature. [Learn more about pricing](https://ngrok.com/pricing).