Kuiu is manufacturer direct. There aren't any resellers with better prices.
Kuiu runs small - and although I want to say an "athletic fit," I'd kinda rather say NOT athletic - as I think of big arms and chest and thighs when I think athletic, and those are the tightest fitting areas in Kuiu. I have a couple of their jackets in large, the chinook, Teton, and Limited softshell, but they fit very snug - I am 5' 10" and running 198lbs currently with a 44" chest, 31" around my belly button. The larges only fit with a t shirt or knit thermals - no way I can get a layering jacket under them. I have XL's in multiple of their jackets for layering, the Chinook, Guide, Kenai, Super Down (since sold this one), and Yukon - these are comfortable for layering, although the super down and kenai do constrict a little in the armpit when under the guide.
I'm happy with the Kuiu stuff for the money. Watch the sales on their site, especially the Outlet, and you can get them very affordably. The Sitka stuff I have was a lot more expensive, although I'll admit, it's kinda nice to have a more "late season" or stand hunting dedicated product in the Sitka than what Kuiu offers. I paid through the nose for the Incinerator jacket and bibs, and they're really only good for TWO temperatures - cold and d@mned cold when not layered and layered, respectively. I paid about the same for the equivalent warmth in Kuiu gear, but have 3 layers to play with in that mix. Sitka seems to run truer to size, but I still tend to get XL's for layering in Sitka too, I just end up a little more baggy. I favor the Kuiu for that quarter size smaller sizing - I'm at the top of a normal large, so them running smaller makes an XL just a little tight when layered and just a little loose when not - so overall a better fit, rather than being just right layered with the Sitka and way too big when not.
I will admit also - I paid a lot less for both parka and bibs for the Cabela's Wooltimate set a couple years ago on after season sale than I paid for just my top or just my bottoms in either Sitka or Kuiu, but I also spend about 3hrs at the end of each season picking weed seeds and burs out of the wool, and the waterproof protection really isn't comparable. For the money, it's a lot cheaper going this route than the Sitka incinerator - wind and warmth are about the same though.
I only have under layers from Firstlite, which I order a little loose so I don't end up itching or end up shrinking out of size. I think they have been pretty true to size for under layers at least.