Part of this affordable "life on the road" concept might also be the fact that gas prices in the US are about 2.5x as cheap as they are in Europe.
(this is always a fun conversion: https://www.google.com/search?q=1.70+euro+per+liter+in+dolla... not sure if that's the most recent gas price here, but it should be about right. This gives $8.36/gallon, and a quick google for gas prices in New York tells me they pay $3.60/gallon)
I've talked to a New Yorker visiting Ljubljana, he was extremely excited about getting a flat for 1700eur/month because that was about half his NYC rent. It was probably one of the ten most expensive flats you can get in Ljubljana. And we have exorbitant rent prices compared to the rest of my home country.
So yeah, I can easily see how an american would think living on the road is super cheap compared to staying home.
Yes, and that's about $100 :) Well okay, it's $91.
Anyway you're right about carpooling. I've noticed that when you're traveling in a group of more than 2 and less than 5, a car is always the best and cheapest option.