Merge branch 'patch-3' of https://github.com/kyjones03/azure-docs into nw-nsgflow

Author: halkazwini

articles/network-watcher/network-watcher-nsg-flow-logging-overview.md

@@ -556,9 +556,17 @@ This problem might be related to:
 
 - **Lack of traffic on your network security groups**: Sometimes you don't see logs because your virtual machines aren't active, or because upstream filters at Application Gateway or other devices are blocking traffic to your network security groups.
 
+## Cost
+
+NSG flow logging is billed on the volume of logs collected. High traffic volume can result in large flow-log volume which increases the associated costs. 
+
+NSG flow log pricing does not include the underlying costs of storage. Using the retention policy feature to hold data for extended periods of time means incurred storage costs last longer. If you want to retain data forever and don't want to apply a retention policy, set retention days to 0. Set the retention policy to your organization's standards.
+
+For more information on costs, see [Network Watcher Pricing](https://azure.microsoft.com/pricing/details/network-watcher/) and [Azure Storage Pricing](https://azure.microsoft.com/pricing/details/storage/blobs/).
+
 ## Pricing
 
-NSG flow logs are charged per gigabyte of logs collected and come with a free tier of 5 GB/month per subscription. For more information, see [Network Watcher pricing](https://azure.microsoft.com/pricing/details/network-watcher/).
+NSG flow logs are charged per gigabyte of "Network Logs Collected" and come with a free tier of 5 GB/month per subscription. If traffic analytics is enabled with NSG flow logs, traffic analysitcs pricing is applicable at per gigabyte processing rates. Traffic Analytics is not offered with a free tier of pricing. For more information, see [Network Watcher pricing](https://azure.microsoft.com/pricing/details/network-watcher/).
 
 Storage of logs is charged separately. For relevant prices, see [Azure Blob Storage pricing](https://azure.microsoft.com/pricing/details/storage/blobs/).