$7.22 – that is current price with coupon for 5V 400mA Solar Panel 2W (in Banggood). Check coupons or create price alert down below. What is best price?
Latest coupon and price update (UTC):
Working voltage: 5V, Working current: 0-400mA, Process: EVA lamination, Output power: 2W, Output port: USB, Product size: 157 * 94mm, Wafer: class A polysilicon, Conversion efficiency: 18.8%, USB cable length: 50cm
Banggood ($7.22)
Banggood warehouse is located in China. I don’t think there is an active coupon right now – at least in my database. Is it a reasonable price for this item? Pretty good price – average ($7.30) is higher than current one!
Link: Banggood product page
Price: $7.22
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k and https://couponsfromchina.com/short/5cd
Old coupons (from the oldest to the newest): BG589b2e
(you can check these old coupons out, but these probably won’t work)
Aliexpress
There’re some similar (or not) items on Aliexpress
Click here to search by yourself. Here are coupons that you can use.
Price history and price alert
Here is price history (for all/most countries) for 5V 400mA Solar Panel 2W.
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)).