This is outside my domain and I don't know how the pricing works out, but AWS Outpost will sell you a physical rack that is fully S3 compatible and redundant to cloud.
The pricing would be prohibitive, I reckon. S3 on Outposts is $0.1/GB/mo, whereas the S3 single zone IA that OP is using as a baseline is $0.01/GB/mo - an order of magnitude less. (Prices are based on us-east-1.)
