Huh? What kind of 500 GB SSD costs $50?
And again--500 GB on EBS is not stored on 500 GB of flash...they use erasure coding and distribute it over ~3x as much, roughly.
Oh, and good luck creating snapshots of your home RAID!
Definitely not $50 to my knowledge but for ~$170 you can get a Samsung 850 EVO which is rated for 98k IOPS. They're fairly reliable drives and much, much faster than anything you'll get on EBS. You could be running that full 3x replication in less than a year of paying for EBS.
> Oh, and good luck creating snapshots of your home RAID!
LVM, ZFS and Btrfs all do snapshotting quite nicely. FreeNAS - commonly used for consumer grade NASes will automatically manage ZFS snapshots for you too. Amazon will sell you extra space to store snapshots, sure, but increasing the size of your devices usually solves that problem. And quite cost effectively as you can probably tell by now...
...and Dropbox can be replaced with SFTP and rsync.
Can you roll your own? Sure. Will it work as reliably and effectively as EBS? Can I scale it easily? How many people are comfortable using snapshots on their own?
It's tried and true tech that any competent ops person can use quite easily. Been around much longer than EBS quite frankly.
Dropbox targets end users who don't have the knowledge required to use the alternative, if you're smart enough to use EBS you're probably smart enough to use ZFS snapshotting just as easily. Or could within a day or two. It's really not that hard.
Like I said, there are systems that pretty much manage the whole thing for you and just warn you when something is about to blow up like FreeNAS.
Oh, and good luck creating snapshots of your home RAID!