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To minimize the cost of virtual machines, especially disk cost, you can consider using Azure Spot Virtual Machines. Spot VMs offer up to 90% cost savings compared to pay-as-you-go prices1. You pay only up to the maximum price you set in advance.
Azure Spot VMs can be terminated if the spot price exceeds your maximum price, so ensure that your workload can handle interruptions.
For your particular use of sponsoring Facebook, you might think about using a smaller, cheaper VM size and managing your disk storage efficiently to save money.
Please refer these Use Azure Spot Virtual Machines.
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