Battery: 1700mAh LiPo (included), CPU: STM32 (max. frequency 72MHz), Charging adapter: 12V / 5V output.
Just check coupons out (with price alert and history). Let’s see what best price is ATM.
Aliexpress
I could not find it on Aliexpress. Click here to search by yourself.
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. One coupon is available. Cool!
Link: Banggood product page
1. ($154.67): BANGGOODSD
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 and https://couponsfromchina.com/short/i1u
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
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Price history and price alert
Price history (for all/most countries) for Xiaomi MITU DIY Robot is here. The lowest price was: $69.34.
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)).
Nice, just bought one, thanks for the coupon! Saved me like a good 20 bucks