The answer to your question is very simple. You broker should volunteer or will if asked print you out comps. In other words if you are looking at a 1995 Catalina 35 ask your broker to print out the sold price for every 35' 1994 to 1996 Catalina 35 for the last year.
Now you will have the supposedly actual price sister boats have sold for recently.
In new cars you can easily lookup the dealer cost and offer a number to the dealer where he makes a fair profit and their will be almost no haggling.
In boating sadly the asking price and the eventual sold price have much less correlation as carrying costs are often so high and emotions run higher. A few years ago 10 percent off asking was almost expected but now there are no rules.
I say supposedly because brokers have a vested interest in keeping the numbers higher and have been known to fiddle a little. It at least gives you an idea.
While you are to to be applauded for not wanting to russel any feathers here I doubt if it will be a problem. If you identify the specific boat you are looking at this community will almost certainly be able to give you better pricing guidelines and more importantly some other makes and models that are comparable that you may not have thought of.
Last edited by davidpm; 11-09-2009 at 06:28 PM.