If you are trying to compare the cost of owning a RV against the cost of vacation alternatives, you certainly need to include the cost of money (financing, depreciation) in the comparison. Those interest payments could be saved for the vacation, and the depreciation will bite you when you try to sell it 8-12 years down the road and you still owe more than the price at which you can sell it.
I started at $58,000, did not have to finance, but the first year's depreciation was at least $8,000 and that $58,000 would have earned another $4800 had I left the money in my stock portfolio. That $12,000 to $13,000 could have bought a lot of vacation that year, considering that the two months of traveling in the RV also cost about $3000 for gas and about $1800 in RV park and campground fees.
The more you use the RV, the better the cost of ownership spreads out as "cost per day" for vacation. We were not doing too badly at first, 60-90 days a year were working out to about $200 per day of vacation. But when my wife got sick and the RV spent more time sitting in storage, the 3-4 weeks a year we could use it came to more like $500 a night. The 2-3 weeks I am using it now work out to a bit less, about $300 a night, because I am going to campgrounds only 18-30 miles away, and at ten years old the annual depreciation is much less.