I ran the numbers when I was four weeks in. (I guess I am at five weeks now)
Just under 4000 miles, forgot to record exact amount.
$752 in gas
16.5 average mpg (dropped a bit, damn)
$129 in overnight costs
$115 in additional food
So a month in and I have had about a thousand in on the road expenses, just over $30 a day.
Of course there are the initial investment costs of the truck and camper, and having the camper has greatly helped in keeping the on the road expenses low. And there is wear and tear on the vehicle, figure that how you may....