Just check coupons out (with price alert and history). Do you want to know what the best price is?
Illumination distance 100m, Voltage range 2.7-4.2V, Lumen 500lm, Battery 1×18650 (not included), Size 120x26x26mm, Material Aluminum alloy, Light source XPL HI 6500K, Charge input current 1A, Brand WAINLIGHT, Endurance time 2.5-50h
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($21.99): BGAlerabatI
2. ($22.49): BGtorch2
apply it in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BG10OFFAFF1, FIN9722, BANGGOODSD, BGTorch4, 00c906, BGtorch3, BGAlerabat15, BGtorch7
(there’s a little possibility that old coupon will work)
Price history and price alert
Do you need price history chart (for all/most countries) for WAINLIGHT BD03 XPL HI 6500K Flashlight? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).