backing up ical calendars can be done by 'export' from the ical menu or saving the files at ~/library/calendars.

and, doesn't isync also back up the files for you [to your .mac a/c] ??

$9 dollars is a little steep to pay someone else to do it for me..

i suppose if 1) you don't have isync, 2) don't have an internet connection, 3) can't remember to back up files, and 4) have more money than sense..
..then this would probably be an ok product