Amazon gets away with high bandwidth pricing because almost all their customers are businesses with high revenue per byte served. If you want to serve large assets economically you have to look elsewhere.
Bandwidth on Oracle Cloud is $0.0085/GB with the first 10TB free each month, so this would have cost only $170. Alternatively bandwidth on Backblaze B2 costs $0.01/GB, but is free out to Cloudflare, so this traffic would have been completely free.