When you are comparing designs and cost, you should remember that the
hull/deck will probably only be about 20% of the final cost.
Keel,spars,engine, sails, etc etc etc etc will not vary too much within
the same displacement range.
Unless you need to build a boat for the satisfaction of constructing it
(like I did), you will be way further ahead (and on the water a lot
quicker) to get a used boat- even one that needs some refurbishing.
Building your own is an expensive way to go, especially if you would be
happy with something that's on the market already.
Check yachtworld.com listings against your shopping list!
My 1-cents worth on building.
John