Hi Stewart,
The $15000 price comes from a new all carbon A cat with 2ft cut off each end. The A cat weighs 165pounds. The hull cross section of a 14ft cat could certainly be no smaller than an A cat because it has to support the same weight and it is 4ft shorter. The 14ft cat hulls would probably be a little fatter than the A cat hulls.
As far as a kit in the US goes: There is little to no market here. Few people build any type boats from scratch anymore. There is no nitch to fill here.
Bill