Aliexpress
Click here… to search for SOFIRN SP31UV 365nm UV Flashlight on Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. There is one great coupon!
Link: Banggood product page
Coupon (35.63 USD): BG10OFFAFF1
(CouponsFromChina.com tip: this code has to be applied 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): BGSF, BGFLS15
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Here is price history (for all/most countries) for SOFIRN SP31UV 365nm UV Flashlight.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).