I have two double volcanos of warmth, 2 Western Mountaineering Pumas for sale. Both are 6' Length, and use Goretex Gore Windstopper (dryloft) material. Excellent condition, no tears, rips, etc. Stored uncompressed in a smoke and pet free home. Both bags are barely used, less than 10 nights total, and have both just been professionally cleaned by a Down specialty company here in Boise (I like to sell anything absolutely clean to a new owner). 

The Puma has a V-block side baffle, a full overstuffed neck down collar, and....incredibly, 2 overlapping full length zipper draft tubes (one on bottom and top). These particular pumas are right zip, and have the original storage sacks. They use the Goretex Windstopper material (gore dryloft as it used to be called). You want the beefier material for these winter bags. Mainly, b/c your tent generally snows from the inside in the winter, where your breath condenses and freezes on the inside of your tent, and when the wind blows, it shakes it off and "snows" on your bag. And, with the goretex windstopper material, you wouldn't ever need to use a bivy with these bags. 

Western Mountaineering doesn't allow retailers to put sales on their bags, so the only way to get one on sale is to buy used. The bag on the left is a 2009, and on the right is a 2007. A 6' Puma GWS is $970 retail plus shipping. I am selling for 30% off...the 2009 for $695 and the 2007 for $670. UPDATE: $650 for the 2009 and the 2007 has now sold!