Aliexpress
Here are coupons that you can use.
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – Xiaomi MR834 Water Purifier S1 [EU] (-3 USD)
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. I found coupon for you. Check this out.
Link: Banggood product page
Coupon (939.12 USD): 6GSGIT
(CouponsFromChina.com tip: put item in your cart and apply coupon code there 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): aff7off, BGMR834, bGpAnDacHeCk, 2020CNY, BGHOMEAPP, bGhOnEy10, 7bcdf9, BGSS10%SW, bgshOOp10, BGHome15%, BGHOMEAPP13, BGHOMEA13, BGCuponation10, BG10OFFAFF, BGwhielabel, BG10OFFAFF1
(I don’t think these’re gonna work, but you can try ’em out anyway)
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – Xiaomi MR834 Water Purifier S1 [EU] (-3 USD)
Price history and price alert
Here is price history (for all/most countries) for Xiaomi MR834 Water Purifier S1.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).