Asking vs Selling price
Unless you are looking at a very rare boat, you should be able to get a general idea of what the boat should sell for by checking yachtworld, boattraderonline, and a few other sites.
I bought a used boat back in June. I searched (casually at first, then more seriously when I became more anxious) for about six months. During that time I watched many boats just sit and site. Eventually the price would drop until it became reasonable, then the boat would sell.
Study the ads for a few months and you will learn what prices the boats are really selling for.
What I don''t understand is why so many list their boats at unreasonably high prices. It takes six months before they drop the price to something reasonable, then the boat sells. However the owners wasted six months!