It doesn't matter whether they charge for the PDI or not, the bottom line total out the door is all that matters. One way or the other, if you expect the dealer to do a competent job of getting the RV ready to go camping and show you how everything works, then you also have to expect that dealer has to make money or he won't be there for long. He can add on all the extras he wants, the only number you need to be concerned with is the total at the bottom. Knock off the PDI whether it's itemized or not, and you can expect to get what you pay for as far as a PDI goes - "here's your keys, see ya!" He sure ain't going to put forth anything when he's losing money doing it.
I actually paid for my PDI, but I also know exactly what I was getting for the money. I got things like 2 full propane tanks, battery, electrical extension cord, and a whole host of things operated, checked out and demonstrated. Bottom line price was what I willing to pay for exactly what I was getting. There was no surprises like "oh the battery is not included".