Added legacy pricing information

Author: rsickles

docs/cloud/reference/03_billing/01_billing_overview.md

@@ -180,6 +180,10 @@ Best for: large scale, mission critical deployments that have stringent security
 
 A ClickHouse Credit is a unit of credit toward Customer's usage of ClickHouse Cloud equal to one (1) US dollar, to be applied based on ClickHouse's then-current published price list.
 
+### Where can I find legacy pricing?
+
+Legacy pricing information can be found [here](https://clickhouse.com/pricing?legacy=true).
+
 ### How is compute metered? {#how-is-compute-metered}
 
 ClickHouse Cloud meters compute on a per-minute basis, in 8G RAM increments.