Looking to find where the cost of the datasyncs we triggered should appear on our invoice

The cost of AWS DataSync operations may not appear as a separate line item on your invoice. Instead, it's likely to be included under broader categories related to data transfer and storage.

For the DataSync service itself, the charges are typically based on the amount of data transferred, charged at a rate per gigabyte. This cost might be grouped under a general data transfer or network category on your invoice.

As for the data transfer costs associated with DataSync operations, these are usually separate from the DataSync service charge itself. Depending on the source and destination of your data transfers, these costs could appear under different headings:

1. If you're transferring data between AWS services in the same region, you might not see additional data transfer charges.

2. If you're transferring data between different AWS regions or from AWS to the internet (or vice versa), you might see these costs under "Data Transfer" or a similar category.

3. When copying data to or from Amazon S3, there may be additional charges for S3 requests (like LIST, HEAD, GET, PUT, COPY) which would appear under Amazon S3 line items.

You are correct in your assumption that the total cost of using DataSync is typically split between the DataSync service charge (priced per gigabyte transferred) and any associated data transfer costs. The exact breakdown and categorization on your invoice may vary depending on the specific details of your DataSync tasks and AWS account setup.

To get a more detailed view of your DataSync costs, you might find it helpful to use AWS Cost Explorer. This tool allows you to filter and group your costs by service, which could help you identify and analyze your DataSync-related expenses more precisely.

Sources
AWS DataSync Pricing | Amazon Web Services
Knowing the differences between Billing and Cost Explorer data - AWS Billing