Is this some kind of personal challenge? It’s arithmetic for chrissakes, not calculus. S3 IA $0.0125/Gb-mo, ingress basically free, $99/yr÷(12mo/yr×$0.0125/Gb-mo)=660 Gb. Reasonable to ignore egress for backups—you may want to account for it, but it’s reasonable to ignore it. Do your own calculations if you have different assumptions.
That’s not hard. The numbers don’t have to be exact.
Maybe I just think it’s easy because I’ve run numbers like these for a living. Given X different storage configurations, under which conditions is configuration 1 cheaper than configurations 2 and 3?
> That's how many businesses work. Many low end gym chains operate on the assumption that most users won't use their services. There's no way that planet fitness can equip and operate a gym for $10/month per member, if everyone one of them went regularly. That doesn't mean it's a bad idea to get a planet fitness membership (assuming you'd actually go), or that they're at risk of going under.
The gym closes I can buy a different gym membership. My cloud storage service closes, it may be difficult to move my data to a different provider, depending on how much data and what kind of rate limits. We’ve seen this before. People with data stuck in an “unlimited” storage service that’s shutting down, trying to transfer it but getting their egress throttled.
The economics of gyms are different because the cost is not only the membership, but also the time it takes you to get to the gym. Cloud services are a much more efficient market, which means the margins are much lower.