They deduplicate and compress before storing, so it may end up only taking 1.5TB.

Still, that's $375/month. Nothing to shake a stick at.

I think the intended use case of tarsnap is for <100 GB raw data that is really important to you, for which you must have an offsite backup that is (according to them) insanely backed up and safe. I could see myself using them for a curated folder of personal documents I can't afford to lose in the event of a house fire. Then again, I could probably fit all my most important documents into my 1Password vault.