Guide
Guide value, comparable sales and what a surveyor adds
Updated
Three sources of value get used and only two of them are worth much. Knowing what each is for stops a negotiation being conducted on the weakest one.
Guide values
Published guides price a model, year and general configuration. They are a legitimate starting point and they cannot see your boat: not the hours, not the moisture, not the fact the electronics were last updated a decade ago.
Use one to establish a base, then expect to move a long way from it in either direction.
Comparable sales, not listings
Boats sit on the market and asking prices drift upward from reality. A comparable that sold tells you what somebody paid; a comparable that is listed tells you what somebody hopes.
Where you can get sale prices, weight them heavily. Where you cannot, treat asking prices as a ceiling rather than a benchmark.
The survey is the real valuation
On any boat more than a few seasons old, a survey moves the number more than any other input. Moisture readings, engine condition and structural findings are the things a buyer cannot see and will not risk.
A written survey with itemised recommendations is also the document a negotiation is actually conducted from, which is why sellers commissioning their own is often worth the cost.
Fix or discount
A seller can rectify findings before listing or discount for them afterwards. Rectifying almost always recovers more, because a buyer deducts the cost of the fix plus a margin for the uncertainty of arranging it.
The exception is a finding so large the boat should be sold as a project, in which case pricing it honestly attracts the buyer who actually wants that.