Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (1567.05 USD): 7bcdf9
Coupon (1567.05 USD): BGSS20SW
(CouponsFromChina.com tip: this code has to be applied in your cart 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): elec, 502C6B, BGBFAFF2019, BGCITYADS2019, bGpAnDacHeCk, BGMPB2020, bGhOnEy10
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Here is price history (for all/most countries) for Beelink Kaby G7 i7-8709G 16/256GB Mini PC.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).