I think you should rethink this position. Dahon is a US company whose primary production facilities are in Taiwan and China. My understanding is that, early in their development, Dahon initially tried (unsuccessfully) to establish US production with some of the then-pervasive US bike manufacturers. None of those companies were interested. Since Dahon did not move production from the US to a foreign country, one can argue that they should not be characterized as "an offshoring US" company. For a US folder for less than $500 see:
http://www.bikeforums.net/newreply.p...reply&t=563167
However, your requirements 3 & 4 might not be met.