The point is to make it easy to move data in and hard to move it out.
A flat fee for the act of a human getting the data onto the physical medium ($200) + the cost of shipping (<$100?) + $15 per day you keep the snowball device past the first + price per GB of data you're transferring ($0.03 per/GB).
So if your getting out 30 TB of data that's $200 + ~$100 + ($0.03 * 30000) = ~$1200
I've been a developer for 10 years and AWS seems to me like its intentionally designed to be as messy as possible.
I am completely unaffiliated with this site, I just enjoy it