$30.99 – High-Impedance Amplifier 1MΩ Input 50Ω Output 0dB Gain 300MHz Bandwidth Long-Lasting Battery Universal Compatibility Ideal for SDR HackRF One Donut Antenna Mini Loop Radio Reception – B.
Right now the best price with coupon code for High-Impedance Amplifier 1Mohm Input 50ohm Output 0dB Gain 300MHz is $30.99 (in Banggood). Check coupons or create price alert down below. Let’s see what best price is ATM.
Latest coupon and price update (UTC):
Banggood ($30.99)
Banggood warehouse is located in China. I don’t think there is an active coupon right now – at least in my database. Is it a low price? According to my database, the average price is $32.66 and current price is $30.99, so it’s probably a good price!
Link: Banggood product page
Price: $30.99
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BGMAI666
(I don’t think these’re gonna work, but you can try ’em out anyway)
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
Click here to search by yourself. Here are coupons that you can use.
Price history and price alert
Here is price history (for all/most countries) for High-Impedance Amplifier 1Mohm Input 50ohm Output 0dB Gain 300MHz. The lowest price was: $29.99.
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)).