We may both have to re-read to see "who's on first". But I think we both said exactly the same thing.
Sorry Minnewaska, yes, I was agreeing with you.
The question of the monetary value of the survey only come in when the buyer pays to get one, turns the boat down and the seller then wants a copy. No way. Not for free.
Also agree. It's the potential buyer's property. A seller can ask for a copy, of course, but it's certainly not owed to him/her.