Comment by bhauer

Perhaps it's pessimistic of me to say so, but I doubt Amazon wants you to be able to appreciate the price relationship with quite this degree of immediacy. Sure, the data is there for you to plot yourself or use a third-party tool such as the OP's. But if you naively select an on-demand instance (the default) where a dedicated instance would be more advantageous for you, Mr. Bezos is made a tiny bit happier.