Aliexpress
Click here… to search for WAINLIGHT BD12 5W 365nm UV 10W LED Flashlight on Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. I found coupon for you. Check this out.
Link: Banggood product page
Coupon (30.79 USD): BGTorch4
(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): BG10OFFAFF1, BANGGOODSD
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Price history (for all/most countries) for WAINLIGHT BD12 5W 365nm UV 10W LED Flashlight is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).