We are running full accounting on everything going into the boats and we can make this available later on..
I am not too keen to present an estimate now, or publish the numbers later on for that matter. Reason is that we know how and where to get parts really cheap and will do most ourself. This will be reflected in the price like Gato said, but not everybody can build to this price unless they have the same connections and skills!
Our estimate is based on finding Tornado masts for less than US$200.
Hulls built from strip plank, which might be cheaper than ply (will be interesting to find out!)
Homemade sails and trampolines
Homemade foils and rudder system
Buying Riley fittings instead of a more well known brand.
Buying all lines in one go, perhaps abroad, and import them at a discount.
Crossbeams probably made in carbon, as we have access to an industrial source for this project. Actually half the price of buying sections from a spar shop and having them shipped here.
None of this would be possible unless we had connections all over the globe helping us out with advice and parts!
Experience with epoxy/wood/composite.
Access to industrial accounts for fibers and epoxy.
A place to build.
Understanding families.

I dont know if I should publish our estimate.. Might do the class more harm than good. Better to wait until we know for sure I think?

Anyway, if somebody wants to build an F16, I would have began sourcing parts. We began with the masts. The hulls are the easy part to build cheap. Finding all the rest is what will break the bank. If one could buy a derelict or wrecked spi cat from an insurance company it might be a good start.