Aliexpress
Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. There is one coupon right now! Check this out.
Link: Banggood product page
Coupon (52.91 USD): BGAudio9
(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): BGMumlatzimP, BGAUDIO, BG9ba0e8, BG1b5830, BGSaleFeb8, BGAudio3, BGSCHOOL8OFF
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Check out price history chart (for all/most countries) for TECSUN GR-88P Digital Radio Receiver.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).