OnePlus 9 Pro 5G 8/128GB Snap888 Global ROM (Banggood, Aliexpress: 5G Chipset: X60, GPU: Adreno 660, Card Extend: No, ROM: 128GB UFS 3.1, CPU: Snapdragon 888 5G (5nm) / Octa-core (1×2.84 GHz Kryo 680 & 3×2.42 GHz Kryo 680 & 4×1.80 GHz Kryo 680, OS: OxygenOS based on Android 11, RAM: 8GB LPDDR5 (the best price with coupon)).
Basically copy coupon, view price history or create e-mail price alert. 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. Hmmm… There is no active coupon in Banggood at this moment.
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!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/feV
Old coupons (from the oldest to the newest): 13f142, BGOP9256D, BGOP9P71Z, BG242e14, BG2a2001, BGc2c16e, BGOP9P128725, BG2e2b11, BGa95942, BG617a81, BG807877, BGbd5384, BG111813, BGe0986f, BG53ac3e, BG2e9546, BG316591, BG5506a5, BG05c7ba, BG7db2e5, BG3c13c0, BG32a0f6, BGcf9598, BG3b1528, BG0c5d7b
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Here is price history (for all/most countries) for OnePlus 9 Pro 5G 8/128GB Snap888 Global ROM. The lowest price was: $669.
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)).