Price history, coupons and price alert are available on this page. You probably want to know what is the best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest price update (UTC time):
Rated Voltage: 14.4V, Water Tank Capacity: 170ml, Mode: CDZB106CN, Battery Capacity: 2500~2600mAh, Mode: BLJ24W200120P-CA, Rated Output: 20V 1.2A, Charging Voltage: 20V, Rated Power: 45W, Charging Time: 4.5h, Battery Type: Li-ion Battery, Rated Input: 20V 1.2A, Mode: B106CN, Adapter: , Rated Output: 20V 1200mA, Rated Voltage: 100-240V, Suction Adjustment: 4gear, Suction: 4000Pa, Charging Base: , Robot Vacuum Cleaner 3C: , Water Volume Adjustment: 3gear, Runtime: 90mins, Dust Box Capacity: 300ml
Banggood
Banggood warehouse is located in China. I am tired of searching coupons, but I found one for you…
Link: Banggood product page
1. ($375.99): BG589b2e
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 and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BG622yb28, BGjuneBR3c, BGAHPU13, BGxiaomi3C, BGeaf456, TTBLACK5
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Price history and price alert
Here is price history (for all/most countries) for Xiaomi Mijia 3C Robot Vacuum Cleaner.
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)).