The coupon price for Xiaomi Mijia Desktop Air Purifier is $116.99 (in Banggood). You can create price alert here, copy coupons and view price history. You probably want to know what is the best price?
Latest coupon and price update (UTC):
Xiaomi Mijia Desktop Air Purifier Original Personal Air Cleaner Antibacterial Purifiers Filtration With Mi Home APP Office Home
Banggood ($116.99)
Banggood warehouse is located in China. Hmmm… There is no active coupon in Banggood at this moment. Low/high price? From what I can see this price is higher than average price ($109.20).
Link: Banggood product page
Price: $116.99
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGBFDAY8, BGNEWYEAR8, BGSPRING8OFF, BGHONEYSP, BGESJY8, BGALL8
(I don’t think these’re gonna work, but you can try ’em out anyway)
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Price history and price alert
Do you need price history chart (for all/most countries) for Xiaomi Mijia Desktop Air Purifier? There we go.
Price records source(s): 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)).