I think the math for Glacier actually gets a lot simpler if you look at it this way: Glacier is only cost effective if you never want to access that data e

I think the math for Glacier actually gets a lot simpler if you look at it this way: Glacier is only cost effective if you never want to access that data ever again. There are actually use cases like this, when you will almost certainly never want to restore this data, but just in case you put it in Glacier. For anything that you expect to ever reasonably want to restore in a reasonable timeframe (like a MySQL database backup), it just doesn't make sense: it's too slow and too expensive.