A mold is only worth something to someone that is going to spend the time/effort to build some hulls, and if someone has the skill/time/money to build hulls, then they could also build a mold I'd think.
I'm sure the molds are worth something, but they are also something that can be built again for a few hundred dollars and time.
Something else, part of the reason Blasters are so great in the surf is the hull design---the v hull/setback pump designs were for racing to compete with the HX, which is not so great in surf. The flatter hull design launches off waves instead of plowing through them.