Im was looking at a pair of Patagonia midweight baselayer bottoms. They were expensive.
They look just like the ECWCS Gen 3 L2 polartech Bottoms that you can pick up for a fraction of capiline. If you compare the prices and material quality to most of the big name companies selling outdoor gear, it pretty much all looks based on the Military system with the addition of unusual colors and little bells and whistles.
https://en.wikipedia.org/wiki/Extend...lothing_System