Which AWS service or tool should the company use?

Explanations:

AWS Budgets is used for setting and tracking budgets for AWS usage and costs, but it does not provide detailed pricing comparisons or cost estimation for specific services like MySQL on EC2 and RDS.

AWS Control Tower is a service for setting up and governing a secure, multi-account AWS environment based on best practices. It does not assist in pricing comparisons for services like MySQL databases.

AWS Outposts is a service that extends AWS infrastructure and services to on-premises locations. It is not relevant for comparing the costs of MySQL databases on EC2 versus RDS.

AWS Pricing Calculator is a tool designed to estimate costs for AWS services. It allows users to input configurations for both EC2 and RDS instances to compare pricing effectively, making it the appropriate choice for this task.