I think $100 a day is a pretty good benchmark, birvine. Yeah, you could go cheaper, but at this stage in my life, I wouldn't want to. Along Hy 101 on the West Coast of the USA, there are a great collection of low cost cyclists campsites-- many with showers. This makes it a pretty cheap tour. Vermont wouldn't be nearly as cheap, I'm guessing (although I still want to ride the Green mountians)

I've toured in Montana where I could camp for free-- but after a couple of days, things got pretty darn stinky. Using motels and pay campgrounds with showers drives up the costs a bunch, but do you really want to wash out your cycling kit in the bathroom at Arbey's? (I did this for a whole trip when I was young and broke BTW)

It's a matter of a person's bank account and comfort level I guess.