What do you think would be fair.
How long is a piece of string? Without knowing make, model, year and seeing the condition and some of the RV's history, there's no way to answer your question. We used to talk about being able to negotiate maybe 26-30% off the price of a new coach, but that was because we collectively had some idea of what the dealer cost was, and possibly what the factory was prepared to kick in. When it comes to used RVs, there's no way of knowing how much the dealer has to work with. Some folks might make a low offer and see if & by how much the dealer responds.
Is this a reputable dealer? I ask because there are many wholesalers out there. When an older vehicle is traded (in part exchange) for a new or newer vehicle, a dealer will often unload it on a wholesaler; They (the dealer) either doesn't want to be bothered with the old vehicle, or feels it's something they can't sell.
A good example is our last motorhome. I knew there were some issues with it that I did not want to pass along to an unsuspecting buyer. I made it a condition of buying our current coach that the dealer took our old one "as is" and at no cost to the dealer. I had to charge them the obligatory $1 to make it a legal sale, but the bill of sale clearly stated all the issues I knew about with the vehicle.
The dealer didn't want to even see the old motorhome, and told me they'd dump it on a wholesaler. Since the wholesaler was closer to me, they had him drive to my house to pick it up. After seeing how he operated and how he talked, there was no doubt in my mind that this guy would try to sell this RV to some unsuspecting buyer, and wouldn't bat an eyelid. The DMV paperwork listed him as a "dealer".
Again the problem with out of state registry is having a mailing address. Any thoughts?
This is where the LLC would make sense. I don't know if just a PO box would even work. OTOH I know of several forum members who are not residents of CA or NV, and who bought a coach in CA , taking delivery in Boomtown. Maybe they can shed some light.