Xiaomi Black Shark 3 12/256GB Global (Banggood, Aliexpress: CPU: Snapdragon 865 + SDX55 Octa Core, , Card Extend: Not Support, GPU: Adreno 650, max to 2.84GHz, RAM: 12GB LPDDR5, ROM: 256GB UFS 3.0, OS: Joy UI 11 based on Android 10 OS (the best price with coupon)).
Basically copy coupon, view price history or create e-mail price alert. Let’s see what best price is ATM.
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 and price update (UTC):
Banggood
Banggood warehouse is located in Hong Kong.
Link: Banggood product page
1. ($652.00): Email5
2. ($652.00): BGHALLOWEEN
you should apply the coupon 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): BG5BS312, BG9BS312
(probably won’t work, but you can try them out)
Price history and price alert
Check out price history chart (for all/most countries) for Xiaomi Black Shark 3 12/256GB Global. The lowest price was: $593.1.
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)).