I'm sorry I neglected to add details about the upload and download costs. Here are my calculations given today's pricing scheme.
In the first case, your total storage usage is 2 GB * 1 month, which at $0.085 per GB month is 2 * $0.085 = $0.17, not $0.65 as you calculated, so that's good news.
Here's a more thorough breakdown of the numbers in the second case, in which data is stored for only short periods. For this example, I'll use the month of April.
To calculate your network costs, let's use the following scenario:
April 1: upload 2 GB of data (uploads are free, no charge)
April 3: download this data to a generic server in the Austin, TX (2GB of download @ $0.12/GB = $0.24)
April 5: remove 2 GB of data (deletes are free, no charge)
April 20: upload 2 GB of data (uploads are free, no charge)
April 21: download 2 GB to a server in Zurich, Switzerland (2GB of download @ $0.12/GB = $0.24)
April 22: remove 2 GB of data (deletes are still free)
This results in a total of $0.48 of network costs (in which we only charge for downloads from cloud storage).
Now we'll calculate your storage costs:
The first set of data, stored from the first to the 5th, is 2 GB over 4 days, which will be billed as 8 GB days. The second 2 GB data set, stored for 2 days, is another 4 GB days. Take those 12 GB days, divide by 30 days per month, and you'll get 0.4 GB months. At $0.085 per GB month, your total storage cost would be $0.034.
To get your total for the month, we add $0.48 + $0.034 and get $0.514, which we round to $0.51.
Of course all of this falls under the free trial tier, so your actual bill would be $0.00.