Now that you can easily fit 3-6TB in an external enclosure, you can do some pretty flexible things with backups.
Here's my system.
Local 3TB drive in system, mirrored to 2nd internal 3TB drive
Nightly, I rsync that data to a 3TB mirrored NAS
Weekly I rsync that data to a 2nd 3TB mirrored NAS
Monthly, I rsync to an external 3TB enclosure via USB
When I go to the bank to deposit checks every month or two, I swap the 3TB external USB enclosure with an identical one in my safe deposit box.
Only costs me $50 a year for the safe deposit box, and I don't have to worry about my neighbors breaking anything.
Also, I have a 2nd manual version of my backup scripts featuring --delete for when storage starts to fill.