The invoice that came with it was $2900. It was supplied with three power vents. That is not what we paid, since they are a contributor to theVAP
Where I ended up mounting mine, the exhaust pipe exits between the main frame rail and the outside edge of the trailer. There was a small cavity there and I removed the insulation. The opening for the exhaust was cut about .75 - 1" bigger all the way around it.
My Ambassador is 28'. I put one vent in the rear bathroom vanity, another under a twin bed in the center of the trailer. And the last out the base of the kitchen cabinet in the front.
I don't have the system completely installed yet, so I have not powered it up.
One thing that should be mentioned and we talked about it on the show, is the Jr. does use the air around it for combustion. So it must be isolated from the living area. I did this by building an air-tight box around it. Its not much different than a fridge really where the rear needs to be isolated from the inside of the trailer as well.
The Jr. does save on space as a seperate furnace and all the ductwork need to support it will not be used. But as you point out, it comes at a cost.