And they'll have to sell 2-3 times that to make at least a "paper" profit. God only knows how many they'd need to sell to make an actual profit, and what are the chances of that when only a few of them in service fly at capacity, and when the 747-8 flies at a lower cost per seat.
It’s more than simple profit. To build the 380, Airbus had to learn to create carbon fiber wings - the largest wings ever attempted out of carbon fiber. When they did this, they learned things that they didn’t know before. This knowledge will carry over to other designs.
If you can make the wings of the 380 out of carbon fiber, you can make other wings for other aircraft using a similar process. This makes future designs more cost effective.
That is progress. If all you do is re-hash an existing design; you are not learning. That is where I’m holding Boeing up to task for. Airbus invested and risked a great deal to develop this aircraft. The lessons learned will make other aircraft better - without having to re-invent the wheel.