I disagree with dtaylor. Making things all inclusive give the dealer to much cover to over charge for the extras. Determine a price you can live with for the unit you want,and stick to it. Remember,you are buying a mass produced product,if you found that one another exists.
"Argue" between the two of you about another unit you saw at a different dealer. Make it believable, have some real knowledge about the other unit. The guy in front of you really does not want you to walk away.
Make it a good offer also do not waste is time or yours with an unworkable figure.
Just as an example, we bought ours at a show, the big yellow sign said
23 something
First thing out of the salesmans mouth brought it to 21000
We offered 16800 trailer alone which set off a period of him and another guy scurrying around,making phone calls and two counter offers both of which were refused
we ended up out the door for 17300 all inclusive,including hitch tag and registration.
Did we get a good deal? I don't know. We were happy!