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 (14.39 USD): BGAMMT03
(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): BGa5c643, BGSCM75, BG589b2e, BGSCM11, BGCAR639
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Do you need price history chart (for all/most countries) for 2pcs Electric Heated Hot Socks? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).