Hey rouslette
check the Azure services you are using for backups. Common services include Azure Backup, Azure SQL Database Backup, and VM backups.
Azure provides various services for backups, and the cost can vary based on your specific configurations of yours
Here is the pricing calculator https://azure.microsoft.com/en-in/pricing/calculator/and it's based on database size. and you can use this to calculate the cot related to your usage.
If this helps kindly accept the answer thanks much.