Using spot pricing you tend to get it far cheaper than that. I was using the previous GPU instances a few months ago which are meant to be $0.65 an hour. But using spot pricing, setting the maximum to about $50 so I wouldn't get shutdown in the middle of training, I seemed to spend an average of about $0.20 an hour.

Now I'm using a P2 instance to see how much faster it runs the same neural net. I set the max price to $0.50 in a spot price bid and got it immediately. I'm not sure how to find out exactly how much it is being charged however.