Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. One coupon is available. Cool!
Link: Banggood product page
Coupon (26.88 USD): BGHOMEAPP13
(CouponsFromChina.com tip: coupon code has to be applied in shop’s 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): 6feb89, 502C6B, vipupgrade8, 0404digoo, 1888CODE, TTxBG10, BGAPPLIANCE, AFfbG10, BGHG522, BGDigoo15%, BGDG15, BGDGFT30, 20%DG422, BGFT2303, BGFTCTY
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Check out price history chart (for all/most countries) for Digoo DG FT2303 Bluetoorh Cooking Thermometer.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).