Please go purchase a Dart or a H16 and sail SMOD.
You will find even here there are constant if not so large of changes. The top level of competition still spend huge money to have new equipment.

I recognize the sales pitch for the F18 class is equality because of the rules, but you are finding this a problem now, why? You have people involved and the largest rule book in the world will not stop people from trying to gain an edge if there competition involved. More rules typically drive cost not the other way around.