Aliexpress
Click here… to search for Xiaomi CosBeauty PerfectGlow Skin Revitalizing Device on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (461.69 USD): BG10OFFAFF
Coupon (503.99 USD): 7bcdf9
(CouponsFromChina.com tip: apply it in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Old coupons (from the oldest to the newest): 502C6B, vipupgrade8, ML15%Pro, BGHC20, bgshOOp10, bGhOnEy10, BGHB20, BgoFErTaSchInA10, BGSD52469, BgcLuBofErtA10, BGAFF10OFF, BGCuponation10
(probably won’t work, but you can try them out)
Price history and price alert
Do you need price history chart (for all/most countries) for Xiaomi CosBeauty PerfectGlow Skin Revitalizing Device? There we go.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).