There are general rules of thumb that says northern boats are cheapest at the end of the summer sailing season, a time when owners are looking at a winter of storage fees
and no useage, or that southern boats are cheapest just before hurricane
season. For the most part these rules of thumb generally apply more as a valid negotiating tool than as a rigid reality. For example in the case of my current
boat, she had been out of commission in Maine
for over a year when I bought her. I began negotiating on her in May but was only able to come to terms on her in late August.
As others said, the reality of any boat deal all depends on the specifics of the boat and owner in question. The key is to develop a list of models that appeal to you and start tracking specific examples of those models. When I am looking for a new boat I typically narrow down the boats that might appeal to me and begin by printing out listings as they come on the market and record
the date that they hit the market. I keep a file or notebook so that I can track specific listings over time to get a sense of how long they are on the market, and also tracking changes in the listing especially when the price
changes. I try to see as many of these boats as I can so that I can get a sense of their relative condition. Over time I develop a sense of the relative value of individual examples of these boats and whether any particular boat appears to be a good deal. This allows me to act quickly, or to sit pat or determine precisely the moment to start negotiating.
If the boat is a mass produced boat, you need to be able to enter a negotiation with the attitude that if this is negotiation does not go the way you want, walk away. Another sistership will come along tomorrow. You were looking for a boat when you entered the negotiation and you still are.
On the other hand, if you have set your sights on a comparatively rare model then you really need to do your homework and be able to strike quickly and perhaps except a deal that is less than ideal.
Your best shot at a great deal occurs when you know what models you want, have your finances in place, and understand that model in terms of availability, typical equipage, endemic problem areas, and average prices.