I use Veritas Netbackup and most backup vendors have tools for Unix/Windows/Mac OSX.
How much does it cost?.
Besides the cost, my experience with the above for 1-2 lic. on Linux -- no interest from the vendor side.
I wrote my own scripts with good old tar as my back end :) The scripts get the job done.
This solution (simple scripts + scheduling) works quite well for a lot a of situations.
Netbackup etc are useful mostly for enterprise. (E.g. automatic off-site backups and management of encryption keys for snapshots on disk as well as tape).
For personal or small business use, Amazon S3 is a useful as well. I am in US for few months and all my data is accessible here since it was backed up on S3. There are lots of tools for Linux, Windows and Even mobile that can sync a filesystem with S3 buckets. And it has an open API too.
-Shamit http://shamit.in