You can create price alert here, copy coupons and view price history. Let’s see what best price is ATM.
Usage Time: 30Minutes, Charging Time: 8 Hours, Voltage: 220V
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 and price update (UTC):
Price history and price alert
There is only one database record (it was for $6.85), so you can’t see price history chart.
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)).