One potential gotcha in your model is egress costs. For the big three, it's anywhere from $0.03/GB to $0.10/GB. The million dollar question suggested by your mo

One potential gotcha in your model is egress costs. For the big three, it's anywhere from $0.03/GB to $0.10/GB. The million dollar question suggested by your model is how do you you store and backup your persistent state in a manner which is not just conceptually robust but cost optimal?