It’s a satellite, where your metadata is stored. To have less latency when your uplink working with metadata (listing for example), it’s better to use a geographically close region. But regarding data - it doesn’t matter too much, data is transferred directly between your uplink and the nodes.
Bandwidth usage calculated for egress (downloads from the network). You will be billed only for settled egress bandwidth (it will be confirmed by nodes and your uplink).
However, since you use a Storj-hosted S3-Compatible Gateway, this overusage is not affecting your limits.
But if you mean using local bandwidth in case of native connection, then yes, the bandwidth will be used from 1 to 110/80 times more than the amount of pieces. There is also expansion factor 80/29 for your actual size of the file during encryption and erasure coding.
1MB * 80/29 ~ 2.76MB
Then it will be uploaded to the nodes
2.76MB * 110/80 = 3.795MB
So bandwidth will be used from 2.76MB to 3.8MB during upload.
However, it’s actual only for a native integration.
For S3 there is no expansion factor on your side and no overusage of bandwidth, all this happening on the GatewayMT with usage of server-side encryption.
In any case you will be billed for storing the original size of your files and settled egress bandwidth.