Fun fact: Using any other public US AWS region would save 3 million dollars per month!
Aside from that: Using infrequent access storage for the parts of the data which don't get frequently accessed would save a lot and I'm pretty sure at that scale AWS would be happy to discuss possible discounts as well.
Aside from that: Using infrequent access storage for the parts of the data which don't get frequently accessed would save a lot and I'm pretty sure at that scale AWS would be happy to discuss possible discounts as well.