Couldn't you just stipulate exactly what you wanted in /var to be backed up to prevent double backups?
For example instead of backing up /var try to backup the following:
I haven't tried it but tonight I had issues with not being able to restore just my /var/www folder, so now I sit and wait for the whole /var folder to be restored...
Nice script, but a bit clunky.
P.S. I haven't tried this myself, no warranty given