Aliexpress
Here are coupons that you can use.
Latest coupon code price check (UTC time):
Banggood
Banggood warehouse is located in China.
Link: Banggood product page
Coupon (12.99 USD): BGJUN214
Coupon (25.74 USD): BG10OFFAFF
Coupon (25.74 USD): BGwhielabel
Coupon (27.60 USD): 13f142
(CouponsFromChina.com tip: paste coupon code in your cart and click Apply after clicking “Proceed to checkout”. Click to copy code and open shop)
Exclusive Allowance Coupons: https://bit.ly/3xWgD9k
Old coupons (from the oldest to the newest): BGLST21, FBCOUPON1, 20%DG422, BGAURN26, BGHome15%, BGHOMEA15%, BGGDJUW5, BGHBHJ105, BGAFF10OFF, BGCuponation10, BGGIGOO, BGIS243X
(sometimes old coupons work, so you can check them out (this site checks them on every price update))
Price history and price alert
Here is price history (for all/most countries) for DIGOO DG-BPSL Solar Powered Camping Lamp.
Price records source(s): Banggood
Click on image to enlarge. 
You can set price alert (for Banggood).