You've misconstrued my entire post. Purchasing a limited-availability device only to exchange it for a different color of the same limited-availability device (even more so, since white isn't avilable) is simply unethical. You've taken a black phone from someone who had otherwise would have been able to purchase if you waited for white, only to exchange it for a white one, which again takes another phone from someone who would have otherwise purchased it. It's selfish. Plain and simple.
What the heck are you talking about?
"You've taken a black phone from someone who had otherwise would have been able to purchase if you waited for white"
Are you serious? Who are you to judge what people do? How do you know that he didn't wait for hours or days camping to get that black iPhone? Will that make it better and "less unethical"? Who's to say he would be able to get a white iPhone? He isn't stealing anything from anyone. He returned the phone and got the other. He doesn't owe you or Apple, anything.
Heck, for all I know I could throw my iPhone into the ocean. Would that be ethically wrong because otherwise my fellow "poor citizen" have been waiting for one?