Wouter,
Scaling hull weights by length to the third power is standard naval architectural practice. It is not something I came up with.
The RC30 hull weight of 175 pounds is a carbon hull. The three beams on the RC30 are aluminum. There are also other parts to consider like ropes and pulleys and wires and spimmaker poles and boards and rudders, etc. All up with sails the boat does weigh 900 pounds. Oh, that includes an outboard motor bracket too. Yes, the other parts of the boat do weigh more than they could but they are not made of carbon. If everything else was made of carbon as the hulls are, one could reduce the weight of the boat by at least another 100 pounds and 'double the price'. If you were the builder, which way would you go? More of these boats are used for recreation than racing. Some of them are even built with fiberglass hulls. The RC27/30 concept is not maxed-out by a long shot. All that is needed in more money.
Wouter, you speak loudly for someone who has never put a boat into production and has no record or facts to stand on. You speak out without knowing all the facts. I find that distasteful.
Bill
Bill