Just check coupons out (with price alert and history). You probably want to know what is the best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Latest coupon code price check (UTC time):
25mW 200mW 600mW Switchable Transmitter Current Sensor Integrated Accessory for RC Drone
Price history and price alert
Price history is not available for this item (not enough database records)! The lowest price was $29.99 though.
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)).