Aliexpress
Click here… to search for Xiaomi SOOCAS LINGLANG S3 Electric Shaver on Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. Well, there is one coupon available right now.
Link: Banggood product page
Coupon (45.16 USD): BGHealth06
(CouponsFromChina.com tip: you should apply the coupon in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Old coupons (from the oldest to the newest): 1bd95d, vipupgrade8, BGS3389, TTxBG10, BG15%SP, AFfbG10, BGS3W33, BGSOOCASSEP, BGBFCR48, BG0841ES, BGBGHFRI15, BGES3343, BGVDay10%off, BGHOMEG12, BGAFF10OFF, bGhOnEy10, BGUFG333, BGdragonBoat, bgshOOp10, BGSJHome43, BGSepPro31, BGHome15%, BGHOMEA15%, BgcLuBofErtA10, BGHBHJ104, 13f142, BGMA1001, BGCuponation10, BGAP0606, BG10OFFAFF, BGMAR1205, BGwhielabel, BGISR045, BGISJY04, BG10OFFAFF1, BANGGOODSD, 6GSGIT
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Price history (for all/most countries) for Xiaomi SOOCAS LINGLANG S3 Electric Shaver is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).