Why not refer to NADA for boat value? Also if you are going thru a broker they have access to previous selling prices however it has been mentioned to take those prices with a lump of salt. And that may be true with NADA. I recently sold our boat. I looked over the listed boats of the same model, considered how much we had in it (more than the listing price) and set a price. I had offers about 2/3 of asking, which I politely countered. I would have countered if the offer was half. The buyer and I went back and forth a few times arriving at a price agreeable to both of us. Now, I could have listed her at a much higher price and waited months for a buyer and in the mean time keep up with maintenance. The surveior found no issues. To the OP, you won't know if the seller will accept your offer until you make it. Don't be shy. You can always offer more but once the offer is accepted you can't offer less....assuming the survey finds no issues.