Hmm... You do not think the companies supplying these millions and millions (across the globe) generators are going to reduce prices with their new higher demand? I do not think it will happen right away but it seems only logical that the price will go down.
Them already having 'good' economy of scale means that any drop in price from the higher demand will be swamped by other, more or less random changes. Changes such as Chinese worker's next pay raise.
Additionally, I suspect that the generator and all of its bracing and attachments would weigh much less than the trailer plus all the attachments.
Trailer wheels don't have to be that heavy, and you don't need a completely through axle. A steering system does add weight though.
As for the battery - I figure that it'd have a standard 12V to start it. You can pull enough energy from an auxiliary plug to run the electronics, but starting an engine is a different ballgame.
There is the issue of cost. Renting them is likely to be the first option.
Twas my first thought. Buying them from the dealer with the car - that's an extra step I'm hesitant on.
As for auxiliary batteries, well, that would quickly exceed the weight allowance of most cars.
As for your RV, if it's draw is 'intense' even when parked, you might have a problem with your electrical.
I most certainly don't see towing multiple trailers - if your RV is a trailer type, put the generator in it! I think I mentioned somewhere of having an adapter kit so you could mount the generator on most trailers assuming you have some room, but I don't think it was here.
Why? Because let's face it - people take RVs camping where there isn't necessarily electricity all the time, there's space for a generator and fuel tank(in most), and it's all round handy. All you have to do is run the wiring so it helps power the towing vehicle.