I think that may be a US thing. At least in Vancouver RV/Camper vans are an expensive luxury unless you're a vandweller.
Insurance runs 1200$/year or more easily, they have to qualify for air care unless they're over 5000kg GVRW, parking is expensive and hard to find if you're downtown, plus there's a lot more break ins.
cargo/window only vans tend to hold their value because they're multi-purpose and useful. They also tend to get used quite hard.
The really good deals on camper-vans come and go quickly, but I've seen nice diesel ones go for 4000$ with new batteries and a decent interior, and two friends have bought good high-roof ones, one for 1200$ one for 800$, while comparable high roof non campers were higher mileage and higher price. Those good deals were all listed for less than a day, people jump on them right away but they do turn up.
Here on the island parking is cheap, insurance is cheap, and campers seem to hold value, because it's easier to hang on to them and wait for the right buyer.