Might want to check how much it costs to increase someone's billing 20k a day (granted, a botnet makes it cheaper, but measure opportunity cost of what else that botnet could be doing), see also https://www.reddit.com/r/aws/comments/7z6uc3/comment/dutgw6u...
AWS Shield (while expensive $36000 a year) does have `DDoS cost protection` as one of it's features. i.e. if you have to 10x your server fleet to outscale + outlast the ddos attack, then AWS will forgive the additional cost.
Might want to check how much it costs to increase someone's billing 20k a day (granted, a botnet makes it cheaper, but measure opportunity cost of what else that botnet could be doing), see also https://www.reddit.com/r/aws/comments/7z6uc3/comment/dutgw6u...
Full disclosure: I work for Azure