Basically copy coupon, view price history or create e-mail price alert. What is the best price?
Latest V9 Version 1.10D Malachite Radio Dual Antenna Malahit-DSP1 Stereo SDR Receiver 50kHz to 250MHz 400MHz to 2GHz
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest price update (UTC time):
Banggood
Banggood warehouse is located in China. You can get coupon down below.
Link: Banggood product page
1. ($231.84): BGHONEYSP
this code has to be applied in your cart after clicking “Proceed to checkout”. Click to copy code and open shop.
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGCAPITALOS8, BG8FORMULAMX, BGBFDAY8, BGNEWYEAR8, BGSPRING8OFF
(system checks these coupons on every price check (like once per 24 hours), but you can check them out anyway)
Price history and price alert
Price history (for all/most countries) for Latest V9 Version 1.10D Malachite Radio Dual Antenna Malahit-DSP1 is here.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood and Aliexpress (only if product name will be the same as on Banggood and I will post it on social media though, so it’s more like Banggood price alert)).