I just sorted through bank records from the time I was away, and thought I'd share what I learned about the expenses of the last two weeks on the road.
I'm not reporting on food, restaurant, or other incidental costs. These are about the same as they would be if I were home. The two major "on the road" expenses are gas and campground fees.
I spent about $400 on gas, and about $130 on camping fees. Total: $530, or for the two weeks I was away, about $38 per day. I was stationary in White Rock with no "camping" fee and very little gas cost while I was there, so the expenses for when I was actually on-the-road were closer to $75 per day.
A reasonable comparison (other than to staying home) might be to car/motel travel. The Beast was getting about 9 miles per gallon, and the Hyundai would have gotten about 30 mpg: so say that my gas cost in the Hyundai would have been about 1/3 of that $400, or $133. Motel costs would be harder to estimate, but even Motel 6 rates for 1 person would be about $50-60 per day. I'd have spent more money on food, since I'd almost certainly have been eating out pretty much all the time, but I'll leave that out of the comparison for now.
So in the car, my daily cost would be about $20 for gas and $55 for motel, or $75 per day. The same per diem cost as camping in the RV.
Simple comparisons break down pretty quick. Staying in Motel 6's for a week would NOT be my idea of a good time; it might be a way to get from Point A to Point B, and if that were my sole purpose I could clearly get there faster at 75 mph on the interstate in the car rather than 60 mph in the RV. Driving in the RV is, for some reason, less fatiguing than in the car. I enjoy camping, even at an RV resort, MUCH more than staying locked up in a motel room. The intangibles make a difference, and they all come out in favor or RV travel, especially when I add back in the fact that I'd be eating "in" a lot more, and probably eating better.
Summary -- while $75 isn't cheap, it's something that I can afford to do. It's a good planning number for future trips done in this style.