Just check coupons out (with price alert and history). What is best price?
organic matter, bacteria, The filtering coverage area: 33 square meters The filter can remove 99.99 percent of PM2.5 particles, etc. Recommend replacing cycle: 3 – 6 months, heavy metal
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
1. ($93.50): 8Couponsde
2. ($93.50): MVC8SPRING
3. ($95.53): BG00c906
you should apply the coupon in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGair1S, bgchinafest, BGnowyfiltr, BGBFAFF2019, BGCITYADS2019, BGHOMEAPP, BGMPB2020, bGhOnEy10, BGAFF7OFF, BGSS10%SW, bgshOOp10, BGXMfilterS1, BGHome15%, BGHOMEAPP12, BGS1XMCZ, BG9XMfilterS1, BGHOMEAPP13, BGXMS1CZ, BGXMFLS1, BGHOMEA13, BGMJAP11, BGS1APFCZ, BGXMS1FLCZ, 13f142, BGAPEHGD, BG10OFFAFF, BGwhielabel, BG6a088e, BG2dd9ee, BG10OFFAFF1, BANGGOODSD, BG9dc3df, 00c906
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Other warehouses/versions
This item is available in 1 another warehouse/version!
1. Europe – Original Green Xiaomi Mi Air Purifier 2 Filter Enhanced Version [EU] ($-3)
Price history and price alert
Here is price history (for all/most countries) for Original Green Xiaomi Mi Air Purifier 2 Filter Enhanced Version.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).