I have just checked coupons. The lowest price I could get is $109.99 for PORTXVNSA 4 inch IPS LCD SA5 Spectrum Analyzer 100k-5.3GHz Signal Generator (in Banggood). Get coupons, create price alert or check price history out! Let’s see what best price is ATM.
Latest coupon code price check (UTC time):
PORTXVNSA 4 inch IPS LCD SA5 Multi-function Handheld Spectrum Analyzer 100k-5.3GHz Signal Generator – No SD Card
Banggood ($109.99)
Banggood warehouse is located in China. I’m afraid that there’s no working coupon in Banggood. Well, is it a good price anyway? Pretty sweet, this is the lowest price I have ever noted for this product!
Link: Banggood product page
Price: $109.99
This is the best price ever noted in my database!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BGALL8
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Price history and price alert
Check out price history chart (for all/most countries) for PORTXVNSA 4 inch IPS LCD SA5 Spectrum Analyzer 100k-5.3GHz Signal Generator.
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)).