Fascinating, so a 1TB sata drive is $70 [1] these days and that equates to about 7 cents per GB, if you made three copies to insure your backups had a 'good' copy that would be 21 cents/gB so its cheaper than using your own hard drives.
The whole 'we've decided to kill that product, you've got 30 days to get your stuff back' and the 'we lost a switch or something and we'll be back online day after tomorrow' kinds of things are still concerns of course.
I've always been impressed at the prices Amazon could charge for S3 and keep it a going concern. I'd love to see the breakout on that revenue but I'm sure that isn't going to happen any time soon.
Oh it gets much worse if you assume that you replace your hard drives every 3 years (their warranty period) which would add a $1.94/month depreciation cost.
You could add into the cost / GB of bandwidth to access the files, not as easy to factor into a TCO model in the personal use case.
It gets better, not worse. At steady state you just account for the depreciation cost, though, right? So that's $1.94/TB/MO/Drive, or $0.0019/GB/MO/Drive or $0.01/GB/MO for 3-way redundancy.
The way I was accounting for it you have to replace the drive in 3 years, you have 3 drives. So you've got a cost of $210 that recurs every three years (purchasing the drives). If you distribute that cost across the 36 months that is a $5.83/month fixed cost (doesn't vary by storage usage because you have to replace the entire drive). Unlike Google which can amortize depreciation on a per-GB basis because they are spreading out the replacements amongst many thousands of drives, as an individual you're on the hook for your own drives regardless.
S3: $0.140 per GB (at the most expensive rate) vs. Google: $0.17 per GB (at their only listed rate)
The rest seems to be the same though.