add note about billing for transaction-based profiling (#13811)

Author: vbro

docs/pricing/index.mdx

@@ -87,7 +87,9 @@ Tracing is enabled by and will be billed for in spans.
 #### Profiling Pricing
 
 Profile Hours are determined by the length of the profile in milliseconds and are billed in hours. Partial hours are prorated and rounded down to the nearest cent. Profile Hours can only be purchased with your PAYG budget.
-
+<Alert>
+  [Transaction-Based profiling](/product/explore/profiling/transaction-vs-continuous-profiling/) is billed under Continuous Profile Hours, by extracting the duration from the samples that make up the profile.
+</Alert>
 **Continuous Profile Hours**
 
 | Team PAYG    | Business PAYG |