Aliexpress
Click here… to search for Syma X5C New Version Quadcopter on 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 (40.81 USD): AFfbG10
Coupon (40.81 USD): BGBFAFF2019
(CouponsFromChina.com tip: paste coupon code in your cart and click Apply after clicking “Proceed to checkout”. Click to copy code and open shop)
Old coupons (from the oldest to the newest): d8f2bb, TTxBG10, 2019SPEDM, bgssaff9, BGCITYADS2019
(there’s a little possibility that old coupon will work)
Price history and price alert
Price history (for all/most countries) for Syma X5C New Version Quadcopter is here.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).