I sent a letter from Japan to Canada for 70 cents. Sending the same letter from Canada to Japan would cost at least $2.50 China must simply have cheaper shippi

I sent a letter from Japan to Canada for 70 cents. Sending the same letter from Canada to Japan would cost at least $2.50 China must simply have cheaper shipping rates, obviously not 3 cents, but probably a fraction of what you are used to spending.