I must be misreading things here: Are we talking about a new Xbox 360 20GB system for $50? What is the downside of this? Is this one of the older models? Does it suffer from the red light of death people keep talking about? This sounds like a great deal if people can find it.
EDIT: Nevermind, I read the title more clearly. It's the Xbox 360 20 HDD. Damn, I got excited there.