Hi Riadh,
Costs might be incurred for ingestion and retention of data in your Log Analytics workspace, depending on your configuration there.
Many alerts are only provided when you've enabled Defender plans for your resources. A good way to preview the alerts you'll get in your exported data is to see the alerts shown in Defender for Cloud's pages in the Azure portal.
Check the pricing structure for the MS Defender for Cloud - https://azure.microsoft.com/en-gb/pricing/details/defender-for-cloud/
Might also you will have cost on the MS Azure Monitor - https://azure.microsoft.com/en-gb/pricing/details/monitor/
Hope this helps.
JS
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