Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. There is one coupon right now! Check this out.
Link: Banggood product page
Coupon (25.08 USD): BGHOMEA13
(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): BGXMRBC, BGXBXMY, 0e7f33, FBCOUPON1, BGHome15%, BGHOMEAPP13
(these coupons are old, so probably won’t work)
Price history and price alert
Do you need price history chart (for all/most countries) for Xiaobai Universal Remote Control Voice Bluetooth Switch? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).