Aliexpress
Click here… to search for BAOFENG BF-K9 Radio Walkie Talkie on Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. There is one coupon available! Pretty cool, huh?
Link: Banggood product page
Coupon (24.24 USD): BG00c906
(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)
Old coupons (from the oldest to the newest): BGHONEY2110, 13f142, BG2589f4, 00c906
(there’s a little possibility that old coupon will work)
Price history and price alert
Here is price history (for all/most countries) for BAOFENG BF-K9 Radio Walkie Talkie.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).