First what do you consider rich?
I would think you need to know the mileage you get on your vehicle. What type of CG you are staying at, the age and mechanical repair of your RV (you will have to anticipate repairs), groceries and eating out, and what places you are visiting, entrance fees etc.
We travelled years ago with friends in almost identical RV's. Our costs were quite a bit different. Their mileage was terrible, we preferred to cook our meals. I think if you gave more details it might help with answers.