I have do disagree with Joel on this one. If a one off or several off, boat is properly built and designed they will sell just as well as a production boat. People are willing to pay for quality. That is my experience having built some boats. Cannot address the brokerage issue, since I sold the boats myself.
But, if it is not well built--to professional standards--then it is very difficult to sell for a number of reasons.
The Caledon certainly looks like a nice boat--and is very well finished (by the photos) by the factory. What would you have different than the factory boat? The Caledon is similar to the Rosoboroug 246, but in some ways roomier. The cabin will be narrower than the C Dory because of the significatly wider side decks. I don't see any layout advantage in the Caledon over the CD 25. The hull formus are different. They seem to give a cruising speed of 15 and top speed of 19 knots--don't know how they will preform at higher speeds or what the fuel economy is.
The costs of a boat finished out by a professional will almost always be more expensive. You will pay the "craftsman" somewhere between $35 to $60 an hour. The factory has templetes, has jigs, and has done this before, so they will do it faster--and are probably paying $10 to $15 an hour....
If you have the skills to do the interior yourself--they you can trade your labor for the savings. Of course you will probably buy a good table saw, a good bandsaw, a planer, shaper and a joiner etc....and there goes your profit, but it is nice to have the tools. Over all you will probably earn $5 to $7 an hour for your labor...