HUAWEI Honor 9X Pro 8/256GB (Banggood, Aliexpress: GPU Mali G52, RAM 8GB, Battery(Built-in) 4000mAh(typ), Display Size 6.59 Inch, ROM 256GB, CPU Hisilicon Kirin 810 Octa core, OS EMUI 9.1.1 (Based on Android 9), Resolution 2340*1080 Pixel, 2×Cortex A76 2.27GHz+6×Cortex A55 1.88GHz (the best price with coupon)).
You can create price alert here, copy coupons and view price history. Best price?
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 China.
Link: Banggood product page
1. ($322.99): Email5
2. ($322.99): bgshOOp10
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/5cd
Old coupons (from the oldest to the newest): BGH9XP2, od7off, BGaDmITAd, BGBFAFF2019, BGMPB2020, BGHALLOWEEN
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Price history (for all/most countries) for HUAWEI Honor 9X Pro 8/256GB is here. The lowest price was: $296.99.
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)).