Aliexpress
Click here… to search for JJRC Q39 Highlander RC Truck on Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (86.21 USD): AFfbG10
Coupon (86.21 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, BGJJRC10, 502C6B
(there’s a little possibility that old coupon will work)
Price history and price alert
Here is price history (for all/most countries) for JJRC Q39 Highlander RC Truck.
Price records source(s): Gearbest, Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).