I think he's quoting that from the other article, not necessarily computing it himself. I think that article was about the cost of broadband + smartphones.

We pay ~$100/month for 1G broadband (I realize this could be lowered somewhat), and ~$100-120 for 5 phone lines for the family (AT&T prepaid). I'd like to see you make a household with multiple lines + broadband work for less than $100-125.

And that's not even that hard - I know some people spend $300+ JUST on their phone plans, in addition to broadband. And then if you factor in amortized cost of phone replacement? It's closer to $200 than to $50 for example, IMHO.