To be fair, though:

"An additional fee is charged once per hour in which at least one Dedicated Instance of any type is running in a Region."

So it's not like they are charging $10/hr/instance (so it amortizes over all of the dedicated instances)

Still, that's 100k a year, not including the cost of the actual instances. Not an option for smaller services unless your stuff simply can't be made to work without dedicated instances.

I doubt it would ever make sense to use this over dedicated servers, except at a large scale.