...It doesn't but I was thinking of making an offer on his boat and would love to know what he paid for it 8 weeks ago. It has nothing to do with my boat.
That makes sense, thanks. Two thoughts:
1) If he bought the boat to flip, he either got a great deal on it, or he's foolish. Flipping boats is not generally a strategy for making money. What improvements he made, if any, should help you judge value, with your knowledge base. If he got a great deal on it, he may be more negotiable.
2) On the other hand, if he's only had it 8 weeks, then I guess the chance he bought it specifically to flip goes up slightly. But if he didn't buy it to flip, then he either really doesn't like the boat, or he has realized he is in over his head, or his circumstances have changed. All of those things help you in negotiations.
Did he list the boat with the same broker that handled his purchase? If not, call the broker that handled the sale to him and ask him straight up what the boat sold for. Worst case, the broker won't tell you. If the same broker is handling this sale, you are much less likely to get the information, but you could ask him why a sale just 8 weeks later.
Finally, if you know a good broker, or can get a recommendation on one (maybe even the one involved in selling your boat to you), call THAT broker and ask him to find out what the boat sold for 8 weeks ago. He'll probably ask why you want to know. Tell him the truth - you may be interested in buying, but are curious about the short interval of ownership and the difference between what he bought for and is listing for. If he's sharp, the conversation becomes an opportunity for him to a) offer his services as a buyer's rep (which you may or may not care about), and b) potentially list a boat (your current one). That may be enough for him to give you the info you want. You haven't misrepresented anything, and you haven't obligated yourself in any way moving forward.