I don't think the price or quality of a coat necessarily has anything to do with how warm it wears.
Perhaps, but not from an utilitarian point of view. A Saxxon wool overcoat, marketed as part of their Winter collection should be warm. I think that's a reasonable expectation. What do I mean by warm? I don't mean I should be sweating my balls off in 20 degree weather with a t-shirt underneath. On the otherhand, when it's 32 degrees I shouldn't feel a breeze with the coat and an undershirt, dress shirt, sweater, and scarf.