I'm selling this minus 40 for $450 shipped to CONUS. Marmot's minus 20 degree bag is about $650.
It has never been used as a sleeping bag. I only occasionally opened as a quilt on top of a bed. It has always been stored in its big cotton bag that lets it loft.
As a feature, you can offset the price of this bag by making bets on how long it takes to put it in its stuff sack. Or take a video of friends trying to stuff it and submit it to Funniest Home Videos. Marmot uses the same stuff sack for this -40 bag as they provide with their -20 bag. It's like wrestling a boa constrictor.
So, a word to the wise - if you aren't using this as a monster quilt and car camping, I suggest buying a larger "backpack" stuff sack.
I bought this with the idea of winter camping and never was in an environment cold enough to require it - but I sleep pretty warm.
Marketing words: The Marmot CWM Sleeping Bag - Down minus 40 Degree, was built for extreme conditions found in places like Alaska and the Himalayas, so you know it'll keep you snug. The Welsh word for cirque or hanging valley is Cwm, like those you'll find in rugged mountains where this bag feels at home.