I don't want to discourage you but I have seen people get these and then panic over the maintenance and repair costs. Unless you can work on this this type of stuff I would suggest researching things like what the costs are for oil changes, transmission fluid changes and brake shoe/pad replacement. 35 quarts of engine oil and 100.00 oil filters are not uncommon. 2000.00 brake jobs are not that uncommon. I work with buses and the company I work for manufactured chassis for some of the above RV manufactures. Here are some things to consider when buying a diesel pusher for the first time. When the engine and transmission are under warranty they are great. I have seen people panic over failed transmissions and engines that were not covered under warranty and they were in the warranty period but the failure was outside of what was covered. A good example which I saw a few of is the transmission cooler fails. That puts antifreeze into the transmission even with the transmission cooler design that is supposed to not let the antifreeze go back into the transmission. I have seen 12,000.00 transmission repairs from this. No one will cover the cost. Complicated system to get into here but it happens. I've seen 15,000.00 engine repairs not covered. Why? Pulling a race car trailer. That's a big hit to eat out of pocket. they also hold a lot of coolant. I have seen 25 gallon systems and on a diesel coolant has to be maintained. On then up side they are fantastic to travel in and will pull mostly anything. if I was to look at a pusher the things I would worry about the most are:
A lot of RV ,manufactures scab on to the rear of the frame and the tongue weight can't be much. I see RV bodies sagging and cracked in the back from trailer tongue weight. Be sure it has a full frame. Fleetwood Dreams and American eagles did.
Some will cut a frame in half and make it any length they need it to be. I have seen some un-solvable tire wear issues because the frame was welded back together wrong.
Radiator and cooling fans. Most have radiators and fan drives that work fine for towing light trailers or using a tow bar to pull a car. Put a heavy trailer on them and the whole cooling system is now marginal at best. They look big when you look at them but space limits a properly sized radiator and fan drive system for towing race trailers that are long and heavy. I'd look for one that has the Modine or EMP electric cooling fan package on it. They work very good.
Electric retarders on a RV are tough to cool. With the body configuration on a pusher it is hard to get air flow to get the heat out of the electric retarder.
Transmission repairs are expensive. Allison is the cheapest to maintain, service, and most everyone can work on the Allison. The German transmissions like Voith or ZF are great transmissions but getting repairs and service is tough. Most Cummins distributors are Voith dealers to. Detroit distributors are Allison dealers to. I'm not talking about the service dealers.
RV manufactures tend to build on a chassis and leave very little access for working on it.
Rear your warranty carefully. Most of this stuff requires you to go to the engine, transmission, axle, AC, manufactures service centers for warranty work.
But what ever extended warranties you can get at the time of purchase. Better to be safe.
Be sure you have road service and towing covered under your insurance, especially tire service.
I can work on them and have past up a few good buying deals over the years. I stick with the Class C type RV because you can go to any parts store and get parts, no worse than a pickup to maintain and have towed if needed. Just have to be sure they also have a full frame. RV manufactures will scab on to the frames using thin metal.
Ben braun
