Just check coupons out (with price alert and history). What is the best price?
Aliexpress
There’re some similar (or not) items on Aliexpress
| Image | Product (link) | Price | Coupons |
|---|---|---|---|
 |
Smile Case For Baseus W04 TWS Case Cover Wireless Bluetooth Headphones Transparent TPU Soft Cover For Baseus W04 Pro Funda Capa | $4.83 | – |
Click here to search by yourself. Here are coupons that you can use.
Latest price update (UTC time):
Frequency Response 20-20kHz, Microphone Yes, bluetooth Version V5.0, Standby Time (h) 350h, Battery Capacity Charging box: 400mAh, Charging Time (h) 1h, Transmission Distance 10m, 3.7V, 3.7V, Earphone: 37mAh*2, Impedance 32Ω, Charging Interface Type-C/ Wireless Charging, Working Time (h) 5h
Banggood
Banggood warehouse is located in China. I’m afraid that there’s no working coupon in Banggood.
Link: Banggood product page
Price: $-3
It looks like this item is out of stock in Banggood. If you found it then please send me the link. I will replace it.
Click here to search on Banggood!
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): AFfbG10, EARSP11, BGTT10, bGhOnEy10, BGSS10%SW, bgshOOp10, BG11SHOP, BG4BW25, BGLOAC1
(you can check these old coupons out, but these probably won’t work)
Price history and price alert
Price history (for all/most countries) for Baseus W04 Pro TWS Bluetooth Earphones is here.
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)).