Aliexpress
Click here… to search for Xiaomi MITU DIY Robot on Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. One coupon is available. Cool!
Link: Banggood product page
Coupon (154.67 USD): BANGGOODSD
(CouponsFromChina.com tip: this code has to be applied in your cart 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): 502C6B, TTxBG10, affbG10, AFfbG10, BGBFAFF2019, BGCITYADS2019, BGMPB2020, BGAFF10OFF, bGhOnEy10, BG3chollox, BGdragonBoat, BGSS10%SW, BGMITU20, bgshOOp10, BGRC902, BgcLuBofErtA10, BGCuponation10, BGHONEY2110, 7bcdf9
(probably won’t work, but you can try them out)
Price history and price alert
Here is price history (for all/most countries) for Xiaomi MITU DIY Robot.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).
Nice, just bought one, thanks for the coupon! Saved me like a good 20 bucks