Anyone else see the potential

There's a TransVan like that down at one of our local self serve wrecking yards. They're pretty cool when fixed up but they can be a real money pit too. If you keep them fairly stock, you can get mileage that isn't too horrible. My '78 Class A motorhome will get 11 on a good day and 9 on a bad one. The class C should get a bit more than that.