If gold hadn't sold out, it would have been a failure. The only function of the gold iPhone is to be hard to get, if it were common as mud, it'd be seen as the bedazzled tacky fashion-gadget shit it is.
I bet you gold isn't going to stay hard to get (harder to get than any other 5s, at least) for very long at all.
Not for too much longer than it takes for the new iPhone to come out, I think.