'Total Cost' of a 360 is however much, or however as little; as a person chooses to spend.
It looks like a choice but there none. Just like any M$ product. Hurray a game console, you can choose not to pay but not be able to play online or to pay and play online. What a choice! All this brings up the total cost of ownership. I am surprised Mac users who bought a Mac just for this reason (total cost of PC is much higher) go ahead and buy a Xbox. That's just stupid.