Aliexpress
Click here… to search for Xiaomi Qin 1S+ Phone on Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. I found coupon for you. Check this out.
Link: Banggood product page
Coupon (100.94 USD): BG55d4b2
(CouponsFromChina.com tip: you should apply the coupon 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): aff7off, fphone, 502C6B, BGREDFSE, BGBFAFF2019, mopro11211, BGCITYADS2019, BGphone3A, Email5, BGVDay10%off, BGMPB2020, bGhOnEy10, BGAFF10OFF, BGdragonBoat, bgshOOp10, BgoFErTaSchInA10, BgcLuBofErtA10, BGCuponation10, 13f142, BGHONEY2110, BGe023a6, BGf87225, BG5225f1, 6GSGIT
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Price history and price alert
Price history (for all/most countries) for Xiaomi Qin 1S+ Phone is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).