smb, they are, that's a fact. It's a common practise that's referred to as the "razorblade model". I think it was Gilette that did it first - Make a loss on the razor to get it in the customers hands then make more profit on the blades, which they have to buy, because they're using your razor.
When PS3 launched it was calculated to cost $800 to manufacture (by iSupply, they a recognized service). Then on top of that you have to add, shipping, tax and retailer margin. Sony had to sell $3 billion worth of shares in their insurance business to float the games division because it made a $900million loss last year. The costs come down over time, the 360 is already considered to be lossless, if not turning a profit after the last price cut. The PS2 has depreciated to teh point that it turns a profit on the device and the Wii is an overclocked Gamecube so it's always made a profit.