The OP raised the generator issue based on the dealer viewpoint. While the dealer isnt necessarily wrong he is also likely expecting to list it at a lower price and move the vehicle quicker. Many people have Honda portable generators and they work well. That is a cheaper option for a buyer. I have used my generator many times in my PW, most recently when we camped at the beautiful Government park on Gabriola Island, BC where there was NO power nor even a dump site. It seems that those who live in hot climates use their generators more than we in temperate climates. I would always include one on an order and, I would lower my price offer if a unit I was trying to buy did not have one. Without one you need either lots of batteries, solar power or a shore power availability. If you always use shore power then you may not use a genset unless the power supply is only 15amp which would be insufficient to run your aircon unit.