Aliexpress
Click here… to search for Xiaomi MiaoMiaoCe Digital Baby Thermometer on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (6.43 USD): MVC8SPRING
Coupon (6.57 USD): BG00c906
Coupon (6.57 USD): BGHB218
(CouponsFromChina.com tip: just apply this code in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): 502C6B, code1573, CODE1573, BGbabyTM, BGHOMEG12, AFfbG10, BGbbtt28, BGmat58, FBCOUPON1, BGAFF10OFF, bGhOnEy10, BGdragonBoat, bgshOOp10, BgoFErTaSchInA10, BGHOMEA15%, BgcLuBofErtA10, BGCuponation10, 13f142, BGHONEY2110, BGZX926, BANGGOODSD, 00c906, BGHealth10D, 2022ACTIESNL
(probably won’t work, but you can try them out)
Price history and price alert
Price history (for all/most countries) for Xiaomi MiaoMiaoCe Digital Baby Thermometer is here.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).