£50 - £60?
You've got a lot of choice, if your looking no more than £20, could go to a super market such as Aldi, Netto, Tesco or Asda, they have some cheap coat which are decent and warm. I tend to buy them cus I ruin my by the end of winter and just get another next year.
If you want something branded, go to any Mall or shopping precinct and there is undoubtfully a shop that sells winter clothing for skiers or adventures, get something from Rockport or Northface for around £50