RAID 5 is overhyped for what it does. You've got much better fault tolerance (not to mention speed) in a RAID 10 setup, but that's off topic.
We use Jungledisk at work, and for the amount we back up (~400GB) we only pay about $90 a month. I also installed it at my local auto shop (which I do PC repair work for as well) and they haven't gone over their basic 5GB plan with Jungledisk yet, and only pay the minimum ($5 or so at most). That's the other nice thing about the basic Jungledisk program, if you opt in with their Rackspace storage, there's no xfer fees, just disk space usage fees (whereas Amazon S3 through Jungledisk charges for bandwidth usage and disk space usage)
The recovery app is easy to use, and I like that you can access your files from anywhere if you have the app installed.
I also use it at home, and I pay about $8 a month right now.