When I am teaching our annual winter cycling classes I always tell people who are looking at riding in the winter that they probably have much of what they need hanging in their closets or tucked in their drawers and that one does not have to spend a lot on specialized cycling gear to stay warm and comfortable in the winter.
I prefer a layered approach and do not own a winter jacket despite my location... a base layer plus an insulating layer (or two) and a windproof and waterproof shell pretty much covers it all and also remind people to avoid cotton as it loses all it's insulating properties when it is wet and does not have many to start with.
Wool can be your best friend as it is an excellent insulator that also stays warm when wet.
Follow my link on winter cycling and you will find a lot more information there.