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 (13.91 USD): BGHOMEA13
Coupon (14.99 USD): 13f142
(CouponsFromChina.com tip: apply it 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): BGLMA09, BGLRA09, 2020CNY, BGLYA09, BGLYA09R, BGVDay10%off, BGAHOFF, BGLRA, BGHOMEAPP, bGhOnEy10, BGSS10%SW, bgshOOp10, BGHome15%, BGHOMEAPP13
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Price history and price alert
Price history (for all/most countries) for LyRay A09 Constant Temperature Cup Mat Base 18W is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).