Just check coupons out (with price alert and history). Do you want to know what the best price is?
Model: KJ500F-T3, Power: 45W, Particulate clean air volume: 500m³/h (actual measured value), Size: 290*290*571 mm, Application area: 41-69㎡, Formaldehyde clean air volume: 313m³/h (measured value), Purification energy efficiency level: high efficiency level, Product noise: 27.5-64.1dB(A), Name: IAM Smart Air Purifier, Accumulated purification amount of formaldehyde: F4, Color: White, Negative ion release: >6.47 million pieces/c㎡, Cumulative purification of particulate matter: P4
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. There is one coupon right now! Check this out.
Link: Banggood product page
1. ($408.57): 7bcdf9
apply it 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): BGSMOFF, bGhOnEy10, bgshOOp10, BgoFErTaSchInA10, BGELIG0920, BgcLuBofErtA10, BGAFF10OFF, BGCuponation10
(these coupons are old, so probably won’t work)
Price history and price alert
Price history (for all/most countries) for IAM KJ500F-T3 45W Smart Air Purifier is here.
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)).