I don't have any personal experience in molding/casting yet, so I can't be absolutely certain, but I don't think a 22" studio-scale kit of the TOS Shuttlecraft would have to be that costly.
Yes, the materials involved would definitely warrant a higher cost (I agree you wouldn't be selling a kit like that for around $100), but at the same time "twice the material" wouldn't necessarily be needed for it.
For instance, the material of choice wouldn't have to be only resin. It could be a combination of fiberglass (upper/bottom hull halves, nacelles) and resin (nacelle support struts, "wings", landing gear).
That way, you can keep the cost of the various parts down -- as trying to cast everything in resin alone would obviously be more expensive as you'd need to buy more of it for all the parts -- and allow it to be built up light and sturdy without any additional engineering/strengthening required.
Another way to keep the cost of such a large kit down would be to keep it strictly accurate to the original filming miniature and avoid any sort of interior. A shell kit consisting of both fiberglass and resin parts would be far more affordable than a kit including a fully detailed interior.
In that case, a seller could offer it both as a bare-bones "screen accurate" kit, with the option of an detailed interior available to those who would want something more in their model. Then you could have it more affordable for most everyone.
Anyway, if it were me that's what I'd do to help make it more easily obtainable to everyone, so I think it is possible. Of course, like I said, I have no experience in the area of kit making, but that's what makes sense to me. Just my thoughts on the matter, fellas.
