Size: 6.01 inches, Resolution: 1080P (2160x 1080 pixels), 401ppi, Aspect Ratio: 18: 9, Type: AMOLED, Supports sRGB, DCI-P3, Cover Glass: 2.5D Corning Gorilla Glass 5, CPU: Snapdragon 835 Octa Core 2.45GHz, RAM + ROM: 8GB RAM + 128GB ROM
Aliexpress
Click here… to search for OnePlus 5T 8/128GB Black on Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in Hong Kong. I don’t think there is an active coupon right now – at least in my database.
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
Price history and price alert
Here is price history (for all/most countries) for OnePlus 5T 8/128GB Black.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).