You can create price alert here, copy coupons and view price history. What is the best price?
Size of the solar panel: 115x 70mm, Light size: 12x 6.8x 6.8cm, Light power: 1.2W, 130lm, continuously effective lighting of fully charged bulb: more than 4h, Color Temperature or Wavelength: 5500 – 6500K
Aliexpress
I could not find it on Aliexpress. Click here to search by yourself.
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Price history and price alert
Check out price history chart (for all/most countries) for Utorch Solar Energy LED Lamp.
Price records source(s): Gearbest
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)).