I heard they WERE selling it at a loss...?
The Wii has much more than the Gamecube, though. Obviously, the innovative Wiimote; Wii-Connect 24; Virtual Console (even though you pay to download games, you can still DO it); the fact that it IS, nevertheless, more powerful than the Gamecube; and the fact that over the years, stuff goes up in price.
It's still the cheapest, even if by 'only' $50. I personally wouldn't let that stop me buying the console I wanted most (just as well that it's not the PS3 I want most, now THAT is bullsh*t).
Sorry if the capitals make me come off as rude, I'm not trying to be, I'm just trying to emphasise.
