Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (104.84 USD): Email5
Coupon (104.84 USD): BGEK99
(CouponsFromChina.com tip: 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
Old coupons (from the oldest to the newest): BG19414e, aff7off, BGTT10, BGNAMEB, bGhOnEy10, BGSS10%SW
(these codes were not working in latest coupon update, but you can check them out anyway)
Price history and price alert
Here is price history (for all/most countries) for Xiaomi MiReader 1/16GB.
Price records source(s): Banggood
Click on image to enlarge.
You can set price alert (for Banggood).