My answer to all questions is more or less the same:
Hell if I know.
Ahem, er, I mean, "It all depends."
- First, it depends upon the condition of the camper -- and not just how it looks, but what condition the bones are in. I've seen a sparkly new "renovation" on a trailer frame that was about to break in half due to rust.
- Next, since we are talking about a vintage product, IF work has been done, was it true to the original design? Especially in a Mobile Scout, if you remove the triangle window... value goes down. If you change the paint scheme... value goes down. These old items have the most general market value when work done to them was intended to maintain the original design details.
- What will the market bear? Are you in an area where camping is hot? Where pulling around a cute little retro is hot? An area with high population? Or out in the middle of nowhere? All these things play a role.
- And perhaps the biggest element -- which some people don't want to/cannot admit? How much do you want to buy it, or sell it? If you see something unique that you really, really want -- then it's worth whatever amount of money you'll take out of your pocket. And if you really, really want to sell it... then you'll set the price to match what someone out there is willing to pay.
Here's a new retro that's listing for almost $10,000. I'll hold my opinion on that, because I'm not in the market to buy a camper, so who cares what I think?
In short, TinCanTourists and other sites that have available campers is the best way to get a ballpark. But if you think you're going to strike it rich with the old mold infested, rotted hulk you found in your cousin's friend's back field... think again. Most of the beautiful renovated campers you see are labors of love.
And worth every penny.