tarsnap is awesome, but it's in no way a replacement for dropbox - their use cases and scenarios where you can use them are entirely different.

If anything is overpriced, tarsnap is -- or was, last time I compared prices. Also picodollars are a bit opaque.

I really wanted to use it and hoped it'd come out reasonably compared to alternatives, but I actually found none except buying a hard disk + raspberry pi myself and hosting it at a friend's place. That was cheaper by about a factor 2, which (at 3TB data) was too much to ignore for my student budget. This was about two years ago though.

That's probably the first time anyone's ever complained about tarsnap being too expensive, honestly. 'tptacek & 'patio11 bang on a lot about it being too cheap, and they're right. tarsnap costs a pretty minimal amount over the underlying S3 storage, but I'm sure if you don't really care about 99.999999999% durability a hard drive on a pi is great too.

Tarsnap's great but it's a backup service not a sync service and is very unsuited for use as a sync service.