On the other hand, the big cost of RVing is usually the fixed cost of owning the RV: license fees, insurance, maybe storage, annual maintenance, and cost of money which includes depreciation and either interest on a loan or lost income on the money that could have been invested (not much return today, but it has been higher).
Since my RV cost $60,000 when I bought it, depreciation and lost earnings were high, pushing fixed costs to at least $3000 a year the first few years, so if I used it 100 days a year, that's another $30 a day. Those costs are down as the value goes down, but if $1500 a year and I only use it 10 days, then $150 a day.