I’m stoked that you’re digging into quilts (so much better than mummy bags!) and have been doing so much research. I love it, and always stoked to nerd out on gear!
Really, really great questions! This kinda got long but here goes:
Why are these things so dang expensive, especially when it’s made in China!?
Having worked for 13+ years in the outdoor industry designing sleeping bags for Marmot, NEMO, etc, I wanted a no compromises product. No more budget driven decisions to cut features. So, we pay quite a bit for the high quality materials, construction technique, and we partner with the best factory and mills to be built to our standards. Out of the dozens of factories I’ve worked with through primo brands, this is the best factory I’ve ever worked with, no matter the product. Awesome quality, well maintained, and best of all they treat their folks well and pay fairly. Luckily we sell mostly direct, so our quilts don’t have to follow the wholesale margins that those other brands require (this thing would likely cost $800+ for them to approve it in the product line)
How much would it cost to be Made in USA?
I’d estimate a Made in the USA version would likely retail for $700-800
As friends of GFC almost since they started, we definitely wanted to be Made in USA, but to accomplish that would’ve taken a heftier investment (millions) to actually get that up and running with our own factory. Soft goods, especially involving down filling and larger products like quilts, is a different beast. Our long term goal is to set up here in the USA as much as we can. For the level of manufacturing technicality quilts require, I haven’t found a factory to approach here. I’ve looked at it and with about 6 - 7$M I can probably set up my own factory. I’ve hunted for partners that can match the quality of our factory we currently work with, but no dice so far – if anyone has connections with potential sleeping bag manufacturing partners in the US, I’d love to chat and see what we can do! 
Enlightened Equipment comparison:
Enlightened equipment is awesome! I’ve used their goods on backpacking trips, and that’s where they shine. A bit small / tight, but perfect for ultralight adventures. As a direct comparison, ours would be in between their 10-20F, and sized XLong. Our quilt is based on 15F sleeping bag construction. We have a ton of individual 3D baffles to reduce down shifting (increases our cost but worth it). With their quilts you’ve gotta work the down more to prevent cold spots.
Probably too deep but … down is a commodity (bi-product of food) and the pricing is a roller coaster. It’s insane how much it’s increased in the last couple years. I’d be very surprised if EE’s prices don’t go up at least $100 this next year once their raw stock is low - ours was locked in at the higher rate, which is why it had to be so expensive from the start. I was hoping we could be $399, but we decided to start our down blanket business at the worst time in history to start a down blanket company 
Long reply but I’d also be stoked to jump on a call and chat more, just DM me.
@venturethewild
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