Hi, @Darragh Martin
To calculate the amount of data that is being sent to Log Analytics from your SQL DB, you can use Log Analytics log queries. You can use the following query to calculate the amount of data that is being sent to Log Analytics from your SQL DB:
AzureDiagnostics
| where Category == "SQLSecurityAuditEvents"
| where ResourceId contains "<your-sql-db-name>"
| where TimeGenerated > ago(1d)
| summarize SizeInMB = sum(_BilledSize) / 1024 / 1024 by bin(TimeGenerated, 1h)
To estimate the cost of sending this data to Log Analytics, you can use the Azure Monitor pricing calculator
https://azure.microsoft.com/en-us/pricing/calculator/?service=monitor%5B1%5D%28#doc-pos=0)%3C/span%3E%3C/span%3E)
Regards
Geetha