$16.99 – Transmission Rate: 50 (Mbps), Distance(L.O.S): 20m, bluetooth version: 5.2+EDR, Size: 49x49x14mm, Material: ABS, Model: TRX30, Effective Working Distance: 10 (m), Color: Black, Whether it is plug and play: Plug and Play.
I have checked all old coupons and price is $16.99 for TRX30 Bluetooth 5.2 Transceiver Audio Transmitter Receiver (in Banggood). Price history, coupons and price alert are available on this page. Do you want to know what the best price is?
Latest coupon code price check (UTC time):
Banggood ($16.99)
Banggood warehouse is located in China. So I have checked for active coupons (all category coupons and old ones), but there was no working coupon in Banggood. Is it a reasonable price for this item? Maybe there’re no more promotions for this item, because current price is higher than average (which is equal $10.32)
Link: Banggood product page
Price: $16.99
Additional Banggood coupons: first page and second page
Old coupons (from the oldest to the newest): BG68b0f4, BG589b2e
(I don’t think these’re gonna work, but you can try ’em out anyway)
Aliexpress
I could not find it on Aliexpress. Click here to search by yourself.
Here are coupons that you can use.
Price history and price alert
Price history (for all/most countries) for TRX30 Bluetooth 5.2 Transceiver Audio Transmitter Receiver is here. The lowest price was: $9.99.
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)).