Let me again jump in here and clarify a few things:
The idea that you can go out and buy a used $15k truck to make this work isnt reality. Most of the bigger legitimate companies that do this require a truck no older than 5 years. That puts you well above the 15k mark for a decent diesel truck.
Secondly the older the truck the more repair and maintenance will be needed raising your costs per mile.
Manufacturers generally as far as I could see dont deliver their own units they contract it out to companies like Horizon.
It is interesting to note that Camping World has it's own delivery company but they cannot keep up with the demand for delivery.
Also The idea that just because some people are doing it means they must be making a profit is flawed. Many I talked to are certainly not business oriented folks who I judged to have no idea if they were making a profit based on our conversations. (I asked one guy what his cost per mile for fuel was and he had no idea...)
But there certainly are folks making a go of it. But as I pointed out above in another response they are those with class A CDL's, larger trucks with sleepers and can haul any kind of unit. They also tend to live close to Indiana and take shorter runs.
Dont misunderstand me I am not saying this never can work. I set out to highlight this as what I experienced as someone experienced in business coming to it as a "work camping" job. I never intended it to be anything more than that.