I was looking at a 200K Benetau a few weeks ago at a boat show, and the whole time I was thinking to myself that there was no way it cost the builder more than 50K to build, but if the market exists that is willing to pay, it makes more sense to build 10, 50K-200K boats a year
Are you sure abut the cost to build a $200K boat? Personally, every time I try to build something myself on the cheap, I wind up spending about 3 times what I had planned and wind up with something that is not satisfactory. I've never tried to build, nor would I, a boat of this type, but I am amazed at how much we get for our money when we buy today's manufactured products, including, but not limited to boats.
There are boats being manufactured in the size range that you mention. A fair number actually. So what's the problem? Just survey the available ones, step up and buy one. i.e. If there were 2 or 3 times as many manufacturers and models available, what would that gain you?