According to my DB the lowest price is $19.98 for Astrolux C8 SST40 Flashlight (in Banggood). Price history, coupons and price alert are available on this page. Best price?
Weight: 151.8g (without battery), Model: C8, Max Output: 2200 Lumens, Emitter Type: SST40, Waterproof: IPX-8 waterproof 2meters, Impact Resistant 1.5M, Light Tint: 5000K (Neutral white), Circuit Driver: A17DD-L FET+1 Driver, 6500K (Cool white)
Latest coupon code price check (UTC time):
Banggood ($19.98)
Banggood warehouse is located in China. I have no active coupons for you right now. Is it a reasonable price for this item? It’s a good price, isn’t it? The average is $20.03.
Link: Banggood product page
Price: $19.98
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGTORCH, BGUA6C8, BGC8A6, BGASTROLUX, BGAC8SST40, BGAST25, BGAFF10OFF, BGCuponation10, 4BLF, BG10OFFAFF, BGwhielabel, BGflashlight, BG10OFFAFF1, BANGGOODSD, BGTorch4, BGYW90, 00c906, BGtorch2, BGtorch3, BGAlerabat15, BGtorch7, BGOutlight10, BG589b2e, BG02d37c
(there’s a little possibility that old coupon will work)
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Price history and price alert
Check out price history chart (for all/most countries) for Astrolux C8 SST40 Flashlight.
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)).