[sigotirandolas]

To avoid penalizing customers who don't use it, they could make you incur an instant overcharge fee when you go over your limit, say 5% of your limit, which would be pooled to compensate for any extra cost Amazon could need to incur to salvage customer data. Like an insurance, fundamentally.

Now that I think about it, a third party could do this as well... except that if it were built in to AWS there would be much less friction.