(Apologies for the long post)....Truth is, in a negotiation like this, we become partners right from the outset. We should treat each other as partners until the negotiations are completed, regardless of the purchase outcome. To me that means we should deal with each other honestly, as we would want to be dealt with, and if something turns up during the course of the process we should both be open to discussing it and coming to a solution that works for both parties.
jasn, your writeup was very good. However, this is the rub. If you've sold enough boats (and aircraft in my case), you can become suspicious of buyers. Many do try to take advantage and nickle and dime the final purchase price for previously disclosed or very obvious items. If you read around this site, you will see some reportedly experienced buyers actually suggesting you do so.
There is nothing wrong with having a surveyor act as your professional advisor, when the buyer lacks the skill themselves. I know quite a bit about most systems, but I would never trust myself to buy without a surveyor. That is most often the case. It's when the buyer made an offer on a 20 year old boat and begins to ask for it to be returned to near new condition that you aren't dealing with a novice, you're dealing with a lack of common sense.
Here's an example. A surveyor may note that a 20 year old seacock shows corrosion, but remains functional, and note it as recommended maintenance down the road. The seller is going to say, no kidding, you will expect to have plenty of maintenance down the road on a 20 year old boat. Some buyers will try to negotiate a price reduction to replace every seacock on the boat, while the survey did not say they had to be replaced now.
Post survey adjustments should be reserved for either undisclosed or unexpected squawks. If the buyer just doesn't like the overall condition of the boat, when the surveyor tells them that they will have lots of maintenance after they buy it, then the expected outcome should be to walk away.
I bought a boat that was advertised literally as an "11 out of 10". Unless that is what the offer says, you can't negotiate for it later.