Aliexpress
Click here… to search for Xiaomi Redmi 20inch Travel Suitcase 38L on Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China. We have found one coupon for this product!
Link: Banggood product page
Coupon (116.99 USD): AFfbG10
(CouponsFromChina.com tip: apply code in your basket (cart) after clicking “Proceed to checkout”. Click to copy code and open shop)
Old coupons (from the oldest to the newest): TTxBG10, BGOD1, BGss11, BGXM9399, BGtravel305, 502C6B, BGbag1023, BGSD13
(there’s a little possibility that old coupon will work)
Price history and price alert
Here is price history (for all/most countries) for Xiaomi Redmi 20inch Travel Suitcase 38L.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).