A very similar jacket is the Mountain Hardwear Sub-Zero ($295). It uses 650-fill downreally, not that different from 700-filland that company's Conduit shell material. And, there's The North Face's Summit Jacket $299. It's similar to both Marmot and Mountain Hardwear in most regards.
Of course, the real sine qua non of down parkas is the Rock & Ice from Feathered Friends. This may be the warmest parka on the planet, with 21 ounces of 750-fill down and a windproof shell with either Epic (a silicon-treated nylon) or PTFE (aka polytetrafluoroethylene, similar in chemical makeup to Gore-Tex). It has a huge hood, a powder skirt, and four big pocketstwo inside and two out, with the inner ones sized to hold one-liter bottlesplus mesh gear stowage bins around the waist. I wore this jacket when I went up Denali, and on summit day I basically used it in place of a rucksack to hold mittens, camera gear, food, and water. It's incredibly warm. But, here's the bad news: the Epic shell will set you back $595, the PTFE $650. The lighter Icefall ($385 with Epic shell) is probably a more versatile piece, and still more than adequate for Denali.
Additional resources: Marmot; The North Face; Mountain Hardwear; Feathered Friends.