Xiaomi JIEZHI Magnetic Electronic Timer (Banggood, Aliexpress: JIEZHI Magnetic Electronic Timer (the best price with coupon)).
You can create price alert here, copy coupons and view price history. Best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
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.
Link: Banggood product page
1. ($17.85): Cuponation9
2. ($17.85): 9OFFSUMMER
3. ($18.44): BG00c906
apply it in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGSAMRTH, BGXP266, BGHome15%, bGhOnEy10, BGHALLOWEEN, BGHOMEA15%, BgcLuBofErtA10, BGAFF10OFF, BGCuponation10, 13f142, BG10OFFAFF, BGwhielabel, BG10OFFAFF1, BANGGOODSD, 6GSGIT, 00c906, BGAlerabat1, Terence, Tabby20, 2203ActiesNL, tRaDetRaCKeR, 8wEbgaInS5, pROMo8cuPoN, BGJUNEGSG9
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Price history and price alert
Do you need price history chart (for all/most countries) for Xiaomi JIEZHI Magnetic Electronic Timer? There we go. The lowest price was: $11.99.
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)).