I could get as much or more processing power out of a Gamecube running a homebrew app vs. the same for this ACube. So if it costs anything over $200 with memory included, it's not worth it.
But can you connect a hard drive and a keyboard+mouse to that gamecube? Will even nitendo let anyone run lets say a OS or a software application on it? I highly doubt so....
The gamecube is just a console, so no wonder why it is cheaper.
It hardly even has any ram, so how can you expect to run anything useful on it?