Moreover, don’t believe those numbers. It is just buzz. If Google pays you 200K, it is not for your PhD, neither for your genius research. It is only about business.
I'm doing this (a PhD in English), but I wouldn't have started if I weren't able to work in my family's consulting business at the same time. Most of my peers in grad school appear to be afraid of the real world and/or diligently putting their head in the sand; now I sent prospective grad students here: http://jseliger.wordpress.com/2012/05/22/what-you-should-kno... and to similar literature on why academia in the liberal arts is an incredibly bad investment.