Compressed backups?

I'm not sure where this thread should go but I had a few questions.

As of recently I have been searching for a cost effective way to back up a large amount of drives (about 10 x 640GB) that reside in a computer that serves the purpose of both data backup and streaming various media types to consoles and computers around the house. I recently borrowed a copy of Acronis True Image Home 2010 from my work's IT dept, but have found that it has no ability to compress the backups which results in a 1:1 data space. I realize that 1:1 backups are probably the most reliable and stable way to backup a system but is there any way/ program that can compress a drive image or a backup that is fairly reliable? and with said compression have the option for incremental backups?

I realize that such an option might just be a hope and a dream, but I really don't want to fork out the $700+ for all the hard drives it would require for a 1:1 backup. The more money I can save the better.

Any help or direction on this topic would be greatly appreciated!

Thanks in advance