1x Relay module.
Price history, coupons and price alert are available on this page. What is the best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
| Image | Product (link) | Price | Coupons |
|---|---|---|---|
 |
ESP8266 ESP-01 5V 12V 1 2 4 Way WiFi Relay Module Things Smart Home Remote Control Switch 1Channel/2Channel/4Channel WIFI Relays | $3.93 | – |
Click here to search by yourself. Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. Well, there is one coupon available right now.
Link: Banggood product page
1. ($9.39): BG00c906
coupon code has to be applied in shop’s cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): 2203ActiesNL, BGJUNEGSG9, Cuponation9
(probably won’t work, but you can try them out)
Price history and price alert
Check out price history chart (for all/most countries) for 5V/12V ESP8266 4 Channels WiFi Relay. The lowest price was: $9.09.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).