You can get HF Linear Power Amplifier 150W for Yaesu FT-817 818 ICOM IC-703 705 XIEGU G90 for $386.39 with coupon (from Banggood). You can create price alert here, copy coupons and view price history. Best price?
HF Linear Power Amplifier 150W for Yaesu FT-817 818 ICOM IC-703 705 XIEGU G90 Automatic Band tester Low-Pass Filter – White
Latest coupon code price check (UTC time):
Banggood ($386.39)
Banggood warehouse is located in China. I think you want to know if the price is good. From what I can see this price is higher than average price ($359.99). Only one coupon available!
Link: Banggood product page
Price without coupon: $389.99
1. ($386.39): BGALL8
just apply this code 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): BGESJY8, BG01adad
(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
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 HF Linear Power Amplifier 150W for Yaesu FT-817 818 ICOM IC-703 705 XIEGU G90.
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)).