Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. You can get coupon down below.
Link: Banggood product page
Coupon (98.85 USD): 13f142
(CouponsFromChina.com tip: apply code in your basket (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): 502C6B, e2bcea, vipupgrade8, TTxBG10, BGss8%hl, bgssaff9, AFfbG10, BGBFAFF2019, BGCITYADS2019, BGHOMEG12, BGMPB2020, BGAFF10OFF, bGhOnEy10, BGdragonBoat, BGSS10%SW, bgshOOp10, BgoFErTaSchInA10, BgcLuBofErtA10, 7d18f7, BGCuponation10
(these coupons are old, so probably won’t work)
Price history and price alert
Here is price history (for all/most countries) for Xiaomi RUSHAN L-DXX002 Electric Breast Pump.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).