Aliexpress
Click here… to search for Xiaomi Smart Frog 1000W Electric Heater on Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (38.55 USD): BGTT10
Coupon (38.55 USD): bGhOnEy10
Coupon (38.55 USD): BGSS10%SW
(CouponsFromChina.com tip: put item in your cart and apply coupon code there 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): BGHOMEAPP, bgshOOp10, BGHome15%, BGHOMEAPP13, BGHOMEA13
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Price history (for all/most countries) for Xiaomi Smart Frog 1000W Electric Heater is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).