I'm giving away some of my secrets here but since we already have what will most likely be our last boat,, I guess we're safe. Here's a couple rules that have served us well over the years.
#1 Knowledge is power. Learn to use resources like Yachtworld and find out what similar yachts are selling for. If using a broker (remember they are ALWAYS working for the seller) make it clear you expect him to provide you with the information you'll need to get the best deal. This might include info like how long has this boat been listed or on the market, or if it is a common design,, what are the things (weaknesses) to look for in this design?
#2 There is no deal that is so good that you can't walk away from it. I know, this takes discipline but by using your resources,, you get a feel for what the boat is worth and how many others there are out there just like the one you're in love with. It's a lot easier to walk away when you know you're getting ripped off or there is a much better deal available on the same yacht just down the road a bit.
Point in case would be our current
PLAN. The seller was a absentee owner while the boat was in Ft. Lauderdale. The negotiations were long and I walked away from the deal three times,,, only to have the seller come back to us each time. The deal was finally sealed with the brokers involved surrendering half of their commission in order to make the numbers work.
The point to remember is that in most cases you don't NEED to buy that particular boat but the seller NEEDS to sell it.