Coldline Storage is a very-low-cost, highly durable storage service for storing infrequently accessed data. Coldline Storage is ideal for data you plan to read or modify at most once a quarter. Since we have a requirement to access data once a quarter and want to go with the most cost-efficient option, we should select Coldline Storage.
Ref: https://cloud.google.com/storage/docs/storage-classes#coldline

https://cloud.google.com/config-connector/docs/how-to/secrets#gcloud

Reference:
https://cloud.google.com/blog/products/gcp/introducing-coldline-and-a-unified-platform-for-data-storage Cloud Storage Coldline: a low-latency storage class for long-term archiving Coldline is a new Cloud Storage class designed for long-term archival and disaster recovery. Coldline is perfect for the archival needs of big data or multimedia content, allowing businesses to archive years of data. Coldline provides fast and instant (millisecond) access to data and changes the way that companies think about storing and accessing their cold data.

https://cloud.google.com/billing/docs/how-to/export-data-bigquery "Cloud Billing export to BigQuery enables you to export detailed Google Cloud billing data (such as usage, cost estimates, and pricing data) automatically throughout the day to a BigQuery dataset that you specify."

Billing Administrators can not create a new billing account, and the project is presumably already created. Project Billing Manager allows you to link the created billing account to the project. It is vague on how the billing account gets created but by process of elimination