Arq is another great alternative, which combined with Amazon Unlimited Cloud Storage, gives you the same benefits as Tarsnap for orders of magnitude less.

Are you talking about this? $59.99/year? https://www.amazon.com/clouddrive/home

And while I've got your attention, 1) are Arq backups encrypted and 2) can it back up via SSH to my own storage somewhere - like a cheap VPS with lots of disk space?

1) Yes. The format and encryption specifics are even documented: https://www.arqbackup.com/arq_data_format.txt

2) Yes. Although if you're after cheap space, Hetzner's storage boxes are the cheapest $/GB I've seen (https://www.hetzner.de/hosting/produktmatrix/storagebox-prod...), with Backblaze B2 close behind.

Any suggestions for an arq like software for linux? Something that does encryption, dedupe, and can target anything.

The problem with some of the really nice solutions on HN, like Tarsnap and Rsync.net is that they're really expensive compared to the alternatives. Tarsnap is $0.25/GB, over 5x the price of standard, 99.999999999% durable S3. Rsync.net is ~8c/GB with the HN discount, still over twice the cost of S3.

Compare that to Backblaze or CrashPlan, which do all your PCs for $5/month.

It gets kinda spendy backing up a whole drive with tarsnap doesn't it? It's blocked for me at work so I can't tell, but I thought it was operating on top of S3. At bare bones s3 pricing that would be $15 a month if I'm not mistaken, for 500GB.