The pricing details on the Hub were out of sync with Amazon since the reductions. There is no premium on reserved instances what so ever. You pay Amazon directly for reserved instances at the price they offer. We have updated the Hub to reflect the reduced pricing - sorry about the confusion.

The Hub currently only supports "Medium reserved instances", as that was Amazon's original offering. Since then Light and Heavy have been introduced. We'll be adding support for the new options to the Hub soon, no ETA yet unfortunately.