Here are the stats from a backup of 1 server with approx 600gig

                   Original size      Compressed size    Deduplicated size

This archive: 592.44 GB 553.58 GB 13.79 MB All archives: 14.81 TB 13.94 TB 599.58 GB

                   Unique chunks         Total chunks

Chunk index: 2760965 19590945

13meg… nice

How about:

A custom package installed from a private repository hosted in Amazon S3