18V 50W PV Solar Panel Charger Kit Monocrystalline Solar Panels with 10 In 1 Adapter Cable.
Aliexpress
There’re some similar (or not) items on Aliexpress
You can use link bot to get even lower price:
| Image | Product (link) | Price | Coupons |
|---|---|---|---|
 |
6.2KW Hybrid Solar Inverters 48V to 230VAC/380VAC Output Parallel UP To 12 Units PV 500VDC With MPPT 120A Solar Controller | $225.22 | – |
Click here to search by yourself. Here are coupons that you can use.
Updated:
Banggood
Warehouse in Europe 
.
Link: 18V 50W PV Solar Panel Charger Kit [EU]
$26.09 with coupon: BGET10
Additional Banggood coupons:
1. First page
2. Second page
Price history and price alert
It doesn’t make sense to generate price history chart, because there is one price record which is: $24.99.
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)).