Aliexpress
Here are coupons that you can use.
Latest coupon and price update (UTC):
Banggood
Banggood warehouse is located in China. You can get coupon down below.
Link: Banggood product page
Coupon (44.13 USD): 13f142
(CouponsFromChina.com tip: apply it in your 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): 502C6B, AFfbG10, BGVDay10%off, BGAFF10OFF, BGTT10, bGhOnEy10, BGdragonBoat, BGSS10%SW, bgshOOp10, BgoFErTaSchInA10, BGELIG0920, BgcLuBofErtA10, BGCuponation10
(probably won’t work, but you can try them out)
Price history and price alert
Price history (for all/most countries) for Baofeng UV-B6 Radio Walkie Talkie is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).