Aliexpress
Click here… to search for RaspberryPi Zero V1.3 Expansion Board on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. I have no active coupons for you right now.
Link: Banggood product page
Price: -3 USD
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Old coupons (from the oldest to the newest): bGhOnEy10, BgoFErTaSchInA10, BGELIG0920, BgcLuBofErtA10, BGRUMB15, BGAFF10OFF, BGCuponation10, 13f142, BGHONEY2110, BGd0b05d
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for RaspberryPi Zero V1.3 Expansion Board.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).
you can get pi zero w for $15 with shipping right now from adafruit
It’s pretty expensive right now on GB. I just added this item, so there is no price history.