You guys didn't mention the region where the sale is offered greatly effects the price, on the east coast the prices south are much cheaper than in the north.
Besides the economic conditions, how many are for sale of same model is relevent, and time in the season. End of season better time to buy.
If you are interested in the best price or best price to value, or the best condition, you pick out say 3-5 of these boats, and evaluate them for condition and usage, options, electronics, motor maintenance records, etc, how far you will have to pay to haul it home, and it's asking price.
You may knock off a few once you come to realize the ad is not reality, then make a list of 1 to whatever with the most desirable on top, make sure you say you are shopping and looking at several offerings.
Then the other members can suggest a startin asking price by percetage below asking, they offer it and see how it floats. Off course you consider and don't ignore repairs that have to be done, add that in. Then do the same with next guy, etc.
If what I described sounds like home buying in current market, yes it is very similar!
When you have a winner and offer accepted, proceed with survey and engine evaluation.
Good luck.