Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (145.53 USD): BGAFF10OFF
Coupon (145.53 USD): bGhOnEy10
(CouponsFromChina.com tip: coupon code has to be applied in shop’s 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): BG8wl10428, TTxBG10, 2019SPEDM, BGWL10, AFfbG10, BGW1124D, BGHU291, 502C6B, BGBFAFF2019, BGCITYADS2019, BGMPB2020
(there’s a little possibility that old coupon will work)
Price history and price alert
Price history (for all/most countries) for Wltoys 10428B RC Car RTR is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).