Aliexpress
Click here… to search for Lumintop SD90 SBT90.2 Flashlight on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. Only one coupon available!
Link: Banggood product page
Coupon (253.09 USD): BGTorch4
(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): BGLMTB, FIN1405, BGwhielabel, BGflashlight, BG10OFFAFF1, BGLMSD90, BANGGOODSD, 6GSGIT
(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 Lumintop SD90 SBT90.2 Flashlight is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).