According to my DB the lowest price is 294.39 USD for 8CH AFHDS 3 (in Banggood). Just check coupons out (with price alert and history). What is best price?
Latest coupon and price update (UTC):
Banggood (294.39 USD)
Banggood warehouse is located in China. But wait a sec… Is it a good price? This price is higher than average price (270.99 USD) for this item. Basically there’re 3 active coupon codes available!
Link: Banggood product page
Price without coupon: 319.99 USD
Coupon (294.39 USD): BGSPRING8OFF
Coupon (294.39 USD): BGHONEYSP
Coupon (299.99 USD): BGbe9fab
(CouponsFromChina.com tip: just apply this code in your cart after clicking “Proceed to checkout”. Click to copy code and open shop)
Aliexpress
Click here… to search for Flysky Noble NB4+ 2.4GHz 8CH AFHDS 3 RC Transmitter on Aliexpress
Here are coupons that you can use.
Price history and price alert
Price history (for all/most countries) for Flysky Noble NB4+ 2.4GHz 8CH AFHDS 3 RC Transmitter is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).