Aliexpress
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
Coupon (400.39 USD): Cuponation9
Coupon (400.39 USD): 9OFFSUMMER
(CouponsFromChina.com tip: 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
Old coupons (from the oldest to the newest): 8Couponsde, tRaDetRaCKeR
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Price history and price alert
Here is price history (for all/most countries) for Blackview BV9800 Pro 6580mAh 6/128GB P70 with Thermal Camera.
Price records source(s): Banggood
Click on image to enlarge.
You can set price alert (for Banggood).