The Google Cloud Pricing Calculator is a tool that allows you to estimate the cost of using Google Cloud products and services based on your specific needs and preferences. You can add various Google Cloud resources to your estimate, such as Compute Engine instances, Cloud SQL instances, network services, storage options, and more. You can also adjust the parameters of each resource, such as the region, zone, machine type, disk size, network egress, and usage hours. The Google Cloud Pricing Calculator will show you the monthly and hourly cost of each resource, as well as the total cost of your estimate. You can also save, share, or export your estimate for future reference.
To create an estimated total cost of cloud infrastructure to run your three-tier web application on Google Cloud instances and Cloud SQL, you should use the Google Cloud Pricing Calculator to determine the cost of every Google Cloud resource you expect to use. You should use similar size instances for the web server, such as n1-standard-1 or n1-standard-2, depending on your application's CPU and memory requirements. You should also use your current on-premises machines as a comparison for Cloud SQL, such as MySQL 5.7 or MySQL 8.0, depending on your database version. You should also consider the network and storage costs associated with your application, such as the network egress, persistent disk, and Cloud Storage.
The other options are not correct because they either do not use the Google Cloud Pricing Calculator, or they do not provide a reliable or accurate estimate of the cloud infrastructure cost. Option B is not correct because creating a Google spreadsheet with multiple Google Cloud resource combinations is a manual and tedious process that may not reflect the current Google Cloud prices or discounts. Option C is not correct because implementing a similar architecture on Google Cloud, and running a reasonable load test on a smaller scale, is a time-consuming and costly process that may not represent the actual load or performance of your application. Option D is not correct because using the Google Cloud Pricing Calculator and selecting the Cloud Operations template will not define your web application with as much detail as possible, as the Cloud Operations template is designed for estimating the cost of monitoring and logging services, not the compute, database, network, and storage services.
Reference:
Google Cloud Pricing Calculator
Compute Engine pricing
Cloud SQL pricing