Where does the money go in an A-cat vs. an F18? for fun, let's see....equipment wise, you loose the jib (-$400), loose the spinnaker (-$800), and gain a carbon mast (+$1200?). So we'll call that even. Price new A-cat $22,000....price new F18 $13,500. Difference $8,500. What you're gaining is a lack of 231 lbs from the platform...soooo you're paying about $37 / lb to go to the lighter a-cat. I'm very pleased with my F18 but considering how easy they are to manuever on land, I still dream about owning a lightweight a-cat one day.
We also need to consider that the production volume is probably pretty low for the a-cat and it uses pricier raw materials to construct. Payback for the tooling is harder to gain back on low volume production.