I'm assuming it factors in total costs for all of the gear and supplies as well. Clearly this will vary depending on how often you camp and how good you are at making your gear last.

We camped out once this past weekend. We have at least 2 more camping weekends planned over the next two months. Obviously (to us anyway) camping is more expensive than just staying where the Marriotts and Starwoods are, because we could do those almost perpetually with $0 (or close to it) actual cash outlay if we so chose. But doing some of both is more fun to us...

This ability to take many different types of vacations is probably the factor that would prevent us from ever buying an RV. With that kind of capital investment, we'd feel compelled to spend every vacation in the RV. It's not just RV's - I've known people who have felt like they're a hostage to a boat or a country club membership. They feel guilty about any weekend when they don't go out on the water or don't play 36 holes of golf.

At least with tent camping, you only have to put a couple hundred bucks into the gear to get started. If you like it or do it often, you can certainly spend more. But it doesn't seem like you have to get invested so deep that you're a slave to it. If we only camp 3 times this summer, we won't feel guilty about it.