Aliexpress
Click here… to search for Xiaomi mijia 3.5K Panorama Action Camera HK on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in Hong Kong.
Link: Banggood product page
Coupon (215.99 USD): elec
Coupon (223.19 USD): aff7off
(CouponsFromChina.com tip: coupon code has to be applied in shop’s cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Old coupons (from the oldest to the newest): 55c495
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Price history and price alert
Do you need price history chart (for all/most countries) for Xiaomi mijia 3.5K Panorama Action Camera HK? There we go.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).