I have written this before but perhaps it might help others again.
I have purchased and owned five RV's over the past 50+ years. As a rancher and owner of a small trucking company, I have also purchased over $2 million cost of ranch and truck equipment over the past decades. Here is the way that I have found that works the best. I have used this always and it works.
First, I research what I am going to buy, type, brand, prices, quality, usage, options, why I need/want it, etc.
Next, I determine what I am will to pay to obtain the item (truck, auto, tractor, RV, machine,etc). I set my price at a figure that will pay the dealer a fair price for profit but not more than necessary.
Then I go to the dealer and if the dealer sells what I want I make an offer before the dealer even mentions a price. My price is always lower than the dealer will ask in his counter price that is usually 15 to 25 percent higher than my offer.
I then pull out my checkbook, offer to write a check to pay in cash on the spot what I have offered, my price, and state take it or leave it since I will walk away. If it is a dealer that has not done business with me before, the dealer will always tell me that he cannot make the deal at my price and try to negotiate. I just get up and walk out. Usually when I start to walk the dealer will then see that I am serious and say to wait. I tell the dealer that my offer is final and unless he is serious I will walk and go to another dealer. I then leave my phone number and walk out.
Usually in about 3/4 of those instances I get a phone call within a day, often within an hour, asking me to come back since the dealer "has been able to work a better price". On the phone I just say my original offer stands and I am on my way to another dealer (true). Unless that dealer tells me on the phone that we can do business at my price I do not go back. Many times I have had a dealer call me a week or so later and tell me that if I had gone back we could have did business. I just tell him (truthfully) that he had his chance and I bought it at another dealer, and tell the price I paid to other named dealer).
Sometimes I even notify the dealer that my offer price is only good that day and after that my offer price drops. I am always willing to walk away and not buy it at all.
Dealers that know me, and we have done business before, know that I mean business and since I have done my research I almost always get the sale at my offered price on the spot. I don't remember every paying close to the Dealer's or MSRP for any major item over the past 50 years. For example our Monty 3750FL 5th Wheel that we now own was purchased at a price 23 percent lower than the price tag price that was prominently shown on the inside counter of the new RV when we first walked into the RV to examine it at the dealer. I never paid even one dollar more than my offer and I got the dealer to add a second AC to the Monty that we bought off the lot before I took delivery.
In 2013 I purchased a new Western Star Semi Truck in Denver and saved over $26,000 from the posted dealer price. I got it with my original offer since the dealer has dealt with me for years and knew that I was serious.
Be a hard nosed buyer and you can save money if you are willing to play the game. Be willing to walk away. Have the cash to pay on the spot, even if you need to get financing before visiting any dealer (I have always paid cash for the deal).
If you are trading an older unit in, do not even mention a trade until you have the new sale completed. Then offer the trade. Since the auto, truck, tractor, machinery dealers in this area know me, they know what I have that I probably will trade in. If they mention or ask if I have a trade I tell them that "I will not discus any trade until, and unless we agree on the new sale".