What makes this any different from me just spinning up my own aws windows server. They must have to mark up prices to make a profit so why not just do it myself? Its an honest question, not a critism.
You only get the advertised rate if you pay the full year in advance. This allows them to advertise a "monthly" rate that is actually "$holycow/12" while also advertising "no commitments!"
edit: and, at 613M of RAM ... I'm not sure exactly what someone would plan to do with such an instance of Windows, but it won't be much.