On your first point, most new things are subsidised by the rich at the start, and end up mass produced so the middle-class can have them, often times becoming commoditised to being in the reach of almost everyone. Computers are a good example. The world hasn't divided because of this. The divisions usually come in the form of "zero-sum" status goods such as high-end brands or jewelery that has little instrumental value.
On the second point, Gattaca is a fictional tale, and as such should not be used as evidence to "show" anything. It is, at best, a hypothesis, and one not optimised for accuracy, or subjected to any scrutiny at that. http://lesswrong.com/lw/k9/the_logical_fallacy_of_generaliza...