Trailer delivery charges are always part of the final price, regardless of whether they are identified by the dealer or not.
Believe me, none of the manufacturers deliver trailers to the dealers for free.
There are about 250,000 towed RVs made each year. The companies all contract to a RV Transport Company to deliver the trailers.
I worked for Classic and then Quality, both are very reputable companies. While I was delivering for Classic, I often picked up JayCos for delivery from the Middlebury plant.
Transport companies charge the manufacturers a per mile cost for delivery. Included in that cost is the transport companies overhead. This overhead includes storage yards amd buildings, insurance, DOT registration and individual registration plates for every trailer they deliver (usually from Minnesota), and paying the often large fees that many States charge in addition to license registration. They also pay for monitoring the drivers as required for the Federal Motor Carrier Safety Administration that includes daily driver logs, physicals, drug testing,etc.
Drivers are paid per mile andreimbursement of actual fees based on receipts submitted. Fees for travel include tolls, fuel tax costs (Saskatchewan is the most) and some State charge to enter into their State even if you are not delivering there. I think NM is $25, AZ is $100, Washington State is $35.00 and in some States (like Idaho and Wyoming) you have buy a temporary registration permit if you don't use their license plates.
The driver is also paid a fuel surcharge based on the current cost of diesel.
Drivers are required to provide their own equipment but it is subject to inspection by both State DOT enforcement police and the companies themselves. There is also a required maintenance inspection by the State of Indiana every six months.
But, the bottomn line, the driver is paid +/- about $1.25 per mile. Some are slightly higher, some slightly lowered. There is additiona pay for Canada, usually .10-.20 per mile.
So, the companys charge the manufacturers somewhere between $2 and $3 per mile. I was never privy to the exact cost but it is a highly competitive business so it is pretty close to what the drivers are paid.
The maufacturers do not use rail transport for several reasons. The first is that there is no rail car designed specifically for an RV. Loading one aboard a car would also be problematic because how do you get the tow vehicle off? The trailers are not stressed for pickup by a crane like a piggyback container is and if they were, they would cost a lot more.
There are no yards for distribution and if there were, who would pay for them? Again, there are only 250,000 trailers made every year by a great number of manufacturers. The costs of maintaining delivery points all over the country and Canada would also be a big problem.
Almost all the transport companies forbid their drivers from entering into or using the trailer while in transit. I never did (I had a crew cab F350 dually with rear changed to a sleeper compartment) but I have seen drivers do it. They invariably get caught or reported and then terminated and I would suspect, blackballed by the transport company.
Drivers are contractors so there are no company benefits. That means they must file their own taxes, pay Social Security and Medicare, keep their own books and for that reason, many are retirees with healthcare provided with their pensions (Medicare and TriCare seem to be the most used)
The old adage is, "if you ain't moving, you ain't making money" holds true for transport drivers. But they have to use the FMCSA rules which means a max of 11 hour driving days and mandatory 34 hours after 70 hours of work.
I was a hobby driver in that I have three retirement pensions (four with SSA) and I still managed to average just over 100,000 miles per year.
The furthest ride I took was a JayCo to Prince George, Britsh Columbia. The longest ride I took was a Raptor toy hauler to Redmond, OR and then a pickup in Pendleton OR with a delivery to Grande Prairie Alberta, return to the US for another pickup at Pendleton OR and a delivery to Lubbock, TX and then finally home to northern Illinois.
I was stopped on Trans Canada 16 east of Edmonton for an 1 1/2 hours while park personnel of the Elk Island Provincial Park moved a herd of 7,000 bison ("You yanks call them buffalo") from the north side of the park to the south side. I had a wolf pack chase a mule deer across the highway in front of me in British Columbia and managed to get my video camera out in time to catch the last two of the pack as they scampered away in pursuit.
I have been stranded on I-80 in Wyoming three separate times because of snow, they just close the highway down and you are stuck where ever you are when it happens. I wnt down I-80 from Indiana headed west 67 times, I headed east 31 times. I have gone down I-65/I-75 17 times and west on I-44 19 times.
The ride back home is unpaid so whatever milage you are paid is for the one way delivery.
Hope this explains the process.
This is a my truck with a 5er in a Utah rest area in 2008:
I finally got fed up paying for repairs/maintenance for my 6.0L turbo diesel ($11,000.00 in 2008 alone) and walked away from the business.