$50/dollars more per month causes that much discomfort?

I wouldn't be too surprised. I spent one summer working in a warehouse. Suffice to say the cars (and their respective rims, sound systems, etc) were not within reasonable spending habits for my fellow $8/hr workers. And their families :(

But the point stands: signaling wealth is what counts.

Of course, there are. The question though is whether there is enough of a correlation with third variables to lead one to believe 'possessing iphone' = 'possessing more sex partners' is likely not causal? As GP and other commenters point out, there are enough.