Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. I found coupon for you. Check this out.
Link: Banggood product page
Coupon (21.78 USD): BG10OFFAFF1
(CouponsFromChina.com tip: paste coupon code in your cart and click Apply 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): BG1655HE, AFfbG10, BG5131, BGCITYADS2019, BGVDay10%off, BGHOMEG12, BGAFF10OFF, FBCOUPON1, bGhOnEy10, BGdragonBoat, BGSS10%SW, bgshOOp10, BGHome15%, BGHOMEA15%, BgcLuBofErtA10, BGCuponation10, 13f142, BGHONEY2110, BG10OFFAFF, BGwhielabel
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Do you need price history chart (for all/most countries) for 3Life NFJ-08 400W Electric Heater? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).