Aliexpress
Click here… to search for Xiaomi YIJIE YS-01 Cleaning Mop on Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. There is one great coupon!
Link: Banggood product page
Coupon (19.54 USD): BGAlerabat1
(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): ff70a8, 502C6B, TTxBG10, aff7off, bgssaff9, AFfbG10, BGBFCR02, BGCITYADS2019, BGBGHFRI15, BGVDay10%off, BGHOMEG12, BGAFF10OFF, bGhOnEy10, BGdragonBoat, BGSS10%SW, bgshOOp10, BGHome15%, BGHOMEA15%, BgcLuBofErtA10, 13f142, BGCuponation10, BGHONEY2110, BG10OFFAFF, BGwhielabel, BG10OFFAFF1, BANGGOODSD, 6GSGIT, BGBF20off2
(probably won’t work, but you can try them out)
Price history and price alert
Price history (for all/most countries) for Xiaomi YIJIE YS-01 Cleaning Mop is here.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).