I've never seen a $100 internet bill that wasn't bundled with other kinds of services.
A more normal number, I think is $50.
If you couple that with the fact that people with out income most likely need to share housing and might as well share in internet connection too, you're already down to $17 per month for broadband.
$50 is more like a starting price; they jack you up to $75 after 6 months (been there, done that).
Also, you're assuming someone has internet service where they live and a stable enough situation to sign up for long-term service. I was thinking more like mobile internet service, which is how people in developing countries use the internet (and they don't pay the ridiculous monthly rates we do either).
A more normal number, I think is $50.
If you couple that with the fact that people with out income most likely need to share housing and might as well share in internet connection too, you're already down to $17 per month for broadband.