[snvzz]

That's just 8 9s. S3 has 11 9s.

[gsibble]

Depends upon your client SLA then. You can also store the file twice on B2 for still less than the cost of S3 :)

[kccqzy]

Will failures be correlated then?

[snvzz]

Then you should be comparing it to reduced redundancy S3, which is cheaper than regular S3.