That’s only true in a nominal sense. Money right now is worth more than money in the future. Money spent on reserved instances is money Amazon has right now, wh

That’s only true in a nominal sense. Money right now is worth more than money in the future. Money spent on reserved instances is money Amazon has right now, whereas net AWS spend from spot instances is money in the future. How much money right now is worth more varies, but Amazon knows best here and prices accordingly.