Nichia NVSL219B, 220 lm, 3500K, Battery Quantity: Built-in 3.7V 500mAh rechargeable Li-ion battery, Mode Memory: Yes, Rechargeable: Yes, Waterproof Standard: IP54.
Just check coupons out (with price alert and history). Best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
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. CouponsFromChina software could not find any coupon for this product in Banggood.
Link: Banggood product page
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): MTIP17
(these coupons are old, so probably won’t work)
Other warehouses/versions
This item is available in 2 another warehouse/versions!
1. China – Nitecore TIP CRI Flashlight Green ($-3)
2. China – Nitecore TIP CRI Flashlight Blue ($-3)
Price history and price alert
Price history (for all/most countries) for Nitecore TIP CRI Flashlight Golden is here. The lowest price was: $15.67.
Price records source(s): Gearbest, 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)).