You can get FX-4CR Radio SDR HF Transceiver for $607.19 with coupon (from Banggood). Basically copy coupon, view price history or create e-mail price alert. Do you want to know what the best price is?
FX-4CR Radio SDR HF Transceiver with 1-20W Continuously Adjustable Power Range Support USB/LSB/CW/AM/FW Modes Short-wave FX4CR （Random Color）
Latest coupon and price update (UTC):
Banggood ($607.19)
Banggood warehouse is located in China. What about the price? From what I can see this price is higher than average price ($603.59). We have found one coupon for this product!
Link: Banggood product page
Price without coupon: $609.99
1. ($607.19): BGALL8
paste coupon code in your cart and click Apply after clicking “Proceed to checkout”. Click to copy code and open shop.
Old coupons (from the oldest to the newest): BGHONEYSP, BGd0dfdc, BGESJY8
(system checks these coupons on every price check (like once per 24 hours), but you can check them 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
Check out price history chart (for all/most countries) for FX-4CR Radio SDR HF Transceiver.
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)).