Xiaomi Mi MIX 3 5G 6/64GB Global Blue (Banggood, Aliexpress: RAM 6GB LPDDR4x, OS MIUI 10, Card Extend Not support, Display Size 6.39 Inch 19.5: 9, ROM 64GB UFS 2.1, max to 2.84GHz, Battery(Built-in) 3800mAh(typ), Resolution 2340*1080 Pixel, CPU Qualcomm Snapdragon 855 Octa Core, GPU Adreno 640 (the best price with coupon)).
Go down and check coupons out. Remember to check price history if it is available. You probably want to know what is the 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 Hong Kong.
Link: Banggood product page
1. ($329.99): BGM35G
2. ($359.99): BGCITYADS2019
3. ($371.99): od7off
paste coupon code in your cart and click Apply after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/feV
Old coupons (from the oldest to the newest): BGMIX35G, BGaDmITAd, BGBFAFF2019
(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
Check out price history chart (for all/most countries) for Xiaomi Mi MIX 3 5G 6/64GB Global Blue. The lowest price was: $329.99.
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)).