Codfish is 敏酤(not sure about the character). They are from the Atlantic. Have you had cod liver oil when you were young? It is the same fish. It has firm, white meat, but must be cooked thoroughly because it might have worms.
It is the cheapest in the supermarkets in the Quebec side. If you can wait until April, it is even cheaper. Market Fresh used to have specials in March and April (down to $3.99 - 4.99 a can) but unfortunately they have already folded.