Ask what kind of transportation they use. Some NWT outfitters use helicopters and/or Argos. Some like that, some don't. I'm not a fan of either but they do get you from area to area quickly.
In 2009 one of their clients and guide were killed in a helicopter accident but I know nothing about the cause other than it was reportedly wind shear. Maybe just bad luck.
NWT sheep hunts are expensive but they are not as rough as the Alaska backpack hunts and the weather tends to be much better. And, you are really in the boonies. Total air fare, tips and all, you're looking at close to $30K, maybe more. If money were no object. I would probably head there with the Yukon as a second choice.