How much does this cost?

TKLBAM and the TurnKey Hub are free. To enable Backups on your TurnKey Hub account you'll need to sign up for cloud storage on Amazon S3 which charges around $0.15/GB per month. Full details of Amazon S3 pricing can be found here.

You can use simulation mode to calculate how much uncompressed data TKLBAM is going to store in a full backup:

$ tklbam-backup --simulate
CREATING /TKLBAM
FULL UNCOMPRESSED FOOTPRINT: 148.30 MB in 6186 files

In practice, the actual footprint of a full backup will usually be smaller due to compression, but this depends on the type of data being compressed (e.g., text compresses very well, video very poorly).

By default, a full backup is performed if one month has passed since the last full backup. In between, incremental backups will be performed which only record changes since the last backup. The full backup frequency can be customized. See this manual page for details.