In thinking more about this, I guess if you compare the cost of an RV to traditional travel, you'll probably come out ahead with the RV.
We have a toyhauler that we make payments on. We have $350/mo budgeted to pay every month, so $4200/year. We only really take it on weekend trips, with the occasional longer trip. So let's say we average $25/night for camp spots (we don't do the fancier RV parks, usually just state parks or boondocking), and we go an average of 36 nights/year (3 nights/month). So that's $900/year. So we're at $5100/year. Then there's gas and food, let's add another $1000/year for that (which is probably too much since the farthest we drive is 4-5 hours). So we're at $6100/year for our travel budget.
We're in our 30s with no kids, and don't take a lot of other vacations, and when we do they are to places to visit family, and cost us in the $300-500 range (Hubs travels for work so when it comes time for pleasure travel, we fly free due to his points). But, compared to some of our friends who take trips to Europe, or friends with kids who do Disney trips or Disney cruises, we're coming out ahead. So I guess if you spin it that way you could argue that an RV is economical. But it's still not an investment. It's all a "throwaway" expense, financially.