We are kind of stuck on this layout....
That shifts the price in the dealer's favor.
The minute we fall in love with a specific car, boat, RV, etc, the competition is gone, and you will usually pay extra for your heart's desire. Dealers and real estate agents love clients who fall in love with a specific model. Is there no other RV with a similar enough layout and features?
If no other will do (quite common), then you have to decide the maximum price you will pay, and be willing to walk away if your price point is not met. And I mean really walk away.
If you actually walk away, the dealer MAY relent on price, fees, etc. Or he may believe there are other out there who will fall in love with the unit the way you did, and are willing to pay a higher price to satisfy the lust.
I have realized in buying houses and having multiple contracts and offers fall through that losing what I thought was my dream house turned out to be good for me, and I ended up with a better house than my first attempts.
Conversely, as a seller of houses, the first offer I get is almost always the best offer. If I don't take the 1st offer, succeeding offers are usually not as good. Most (but not all!) dealers recognize this, and will try to keep the 1st reasonable offer from walking away.
I ended up buying my A-frame new from a fixed price dealer because the sellers of used A-frames were being unreasonable.
Fred W
2019 Flagstaff T21TBHW A-frame
2022 Hyundai Palisade