Explanation

The AWS Pricing Calculator is the correct choice because:

• Purpose: It's specifically designed for estimating AWS costs before actual deployment
• Use Case: Perfect for early planning stages when you need to predict monthly costs for future resources like EC2 instances and storage
• Functionality: Allows users to model AWS services and get detailed cost estimates

Why not the other options:

• AWS Compute Optimizer: Analyzes existing EC2 instances to recommend optimal configurations for cost savings, but doesn't provide cost predictions for future deployments
• AWS Trusted Advisor: Provides real-time guidance on cost optimization, security, and performance for existing AWS resources
• AWS Application Migration Service: Helps migrate applications to AWS but doesn't provide cost estimation capabilities

For migration planning and cost prediction, AWS Pricing Calculator is the appropriate tool to estimate total cost of ownership for future AWS resources.