Aliexpress
Click here… to search for Xiaomi MITU Finger Spinner Toy on Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. I don’t think there is an active coupon right now – at least in my database.
Link: Banggood product page
Price: -3 USD
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Old coupons (from the oldest to the newest): BGCUBERA, BGAFF10OFF, bGhOnEy10, BGdragonBoat, BGSS10%SW, BgoFErTaSchInA10, BgcLuBofErtA10, 451feb, BG10OFFAFF, BGwhielabel, 13f142, BG10OFFAFF1, BG4d9120
(I don’t think these’re gonna work, but you can try ’em out anyway)
Price history and price alert
Check out price history chart (for all/most countries) for Xiaomi MITU Finger Spinner Toy.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).